Lojban (pronounced “LOZH-bahn”) is a constructed language. Previous versions of the language were called “Loglan” by Dr. James Cooke Brown, who founded the Loglan Project and started the development of the language in 1955. The goals for the language were first described in the open literature in the article “Loglan” , published in Scientific American , June, 1960. Made well-known by that article and by occasional references in science fiction (most notably in Robert Heinlein's novel The Moon Is A Harsh Mistress) and computer publications, Loglan and Lojban have been built over four decades by dozens of workers and hundreds of supporters, led since 1987 by The Logical Language Group (who are the publishers of this book).

There are thousands of artificial languages (of which Esperanto is the best-known), but Loglan/Lojban has been engineered to make it unique in several ways. The following are the main features of Lojban:

This book is what is called a “reference grammar”. It attempts to expound the whole Lojban language, or at least as much of it as is understood at present. Lojban is a rich language with many features, and an attempt has been made to discover the functions of those features. The word “discover” is used advisedly; Lojban was not “invented” by any one person or committee. Often, grammatical features were introduced into the language long before their usage was fully understood. Sometimes they were introduced for one reason, only to prove more useful for other reasons not recognized at the time.

By intention, this book is complete in description but not in explanation. For every rule in the formal Lojban grammar (given in Chapter 21), there is a bit of explanation and an example somewhere in the book, and often a great deal more than a bit. In essence, Chapter 2 gives a brief overview of the language, Chapter 21 gives the formal structure of the language, and the chapters in between put semantic flesh on those formal bones. I hope that eventually more grammatical material founded on (or even correcting) the explanations in this book will become available.

Nevertheless, the publication of this book is, in one sense, the completion of a long period of language evolution. With the exception of a possible revision of the language that will not even be considered until five years from publication date, and any revisions of this book needed to correct outright errors, the language described in this book will not be changing by deliberate act of its creators any more. Instead, language change will take place in the form of new vocabulary – Lojban does not yet have nearly the vocabulary it needs to be a fully usable language of the modern world, as Chapter 12 explains – and through the irregular natural processes of drift and (who knows?) native-speaker evolution. (Teach your children Lojban!) You can learn the language described here with assurance that (unlike previous versions of Lojban and Loglan, as well as most other artificial languages) it will not be subject to further fiddling by language-meisters.

It is probably worth mentioning that this book was written somewhat piecemeal. Each chapter began life as an explication of a specific Lojban topic; only later did these begin to clump together into a larger structure of words and ideas. Therefore, there are perhaps not as many cross-references as there should be. However, I have attempted to make the index as comprehensive as possible.

Each chapter has a descriptive title, often involving some play on words; this is an attempt to make the chapters more memorable. The title of Chapter 1 (which you are now reading), for example, is an allusion to the book English As We Speak It In Ireland , by P. W. Joyce, which is a sort of informal reference grammar of Hiberno-English. “Lojbanistan” is both an imaginary country where Lojban is the native language, and a term for the actual community of Lojban-speakers, scattered over the world. Why “mangle” ? As yet, nobody in the real Lojbanistan speaks the language at all well, by the standards of the imaginary Lojbanistan; that is one of the circumstances this book is meant to help remedy.

Each chapter is broken into numbered sections; each section contains a mixture of expository text, numbered examples, and possibly tables.

The reader will notice a certain similarity in the examples used throughout the book. One chapter after another rings the changes on the self-same sentences:

will become wearisomely familiar before Chapter 21 is reached. This method is deliberate; I have tried to use simple and (eventually) familiar examples wherever possible, to avoid obscuring new grammatical points with new vocabulary. Of course, this is not the method of a textbook, but this book is not a textbook (although people have learned Lojban from it and its predecessors). Rather, it is intended both for self-learning (of course, at present would-be Lojban teachers must be self-learners) and to serve as a reference in the usual sense, for looking up obscure points about the language.

It is useful to talk further about Example 1.1 for what it illustrates about examples in this book. Examples usually occupy three lines. The first of these is in Lojban (in italics), the second in a word-by-word literal translation of the Lojban into English (in boldface), and the third in colloquial English. The second and third lines are sometimes called the “literal translation” and the “colloquial translation” respectively. Sometimes, when clarity is not sacrificed thereby, one or both are omitted. If there is more than one Lojban sentence, it generally means that they have the same meaning.

Words are sometimes surrounded by square brackets. In Lojban texts, these enclose optional grammatical particles that may (in the context of the particular example) be either omitted or included. In literal translations, they enclose words that are used as conventional translations of specific Lojban words, but don't have exactly the meanings or uses that the English word would suggest. In Chapter 3 , square brackets surround phonetic representations in the International Phonetic Alphabet.

Many of the tables, especially those placed at the head of various sections, are in three columns. The first column contains Lojban words discussed in that section; the second column contains the grammatical category (represented by an UPPER CASE Lojban word) to which the word belongs, and the third column contains a brief English gloss, not necessarily or typically a full explanation. Other tables are explained in context.

A few Lojban words are used in this book as technical terms. All of these are explained in Chapter 2 , except for a few used only in single chapters, which are explained in the introductory sections of those chapters.

It is necessary to add, alas, that the examples used in this book do not refer to any existing person, place, or institution, and that any such resemblance is entirely coincidental and unintentional, and not intended to give offense.

When definitions and place structures of gismu, and especially of lujvo, are given in this book, they may differ from those given in the English-Lojban dictionary (which, as of this writing, is not yet published). If so, the information given in the dictionary supersedes whatever is given here.

Although the bulk of this book was written for the Logical Language Group (LLG) by John Cowan, who is represented by the occasional authorial “I” , certain chapters were first written by others and then heavily edited by me to fit into this book.

In particular: Chapter 2 is a fusion of originally separate documents, one by Athelstan, and one by Nora Tansky LeChevalier and Bob LeChevalier; Chapter 3 and Chapter 4 were originally written by Bob LeChevalier with contributions by Chuck Barton; Chapter 12 was originally written (in much longer form) by Nick Nicholas; the dialogue near the end of Chapter 13 was contributed by Nora Tansky LeChevalier; Chapter 15 and parts of Chapter 16 were originally by Bob LeChevalier. The BNF grammar, which is also in Chapter 21 , was originally written by me, then rewritten by Clark Nelson, and finally touched up by me again.

The research into natural languages from which parts of Chapter 5 draw their material was performed by Ivan Derzhanski. LLG acknowledges his kind permission to use the fruits of his research.

The pictures in this book were drawn by Nora Tansky LeChevalier, except for the picture appearing in Chapter 4 , which is by Sylvia Rutiser Rissell.

The index was made by Nora Tansky LeChevalier.

I would like to thank the following people for their detailed reviews, suggestions, comments, and early detection of my embarrassing errors in Lojban, logic, English, and cross-references: Nick Nicholas, Mark Shoulson, Veijo Vilva, Colin Fine, And Rosta, Jorge Llambias, Iain Alexander, Paulo S. L. M. Barreto, Robert J. Chassell, Gale Cowan, Karen Stein, Ivan Derzhanski, Jim Carter, Irene Gates, Bob LeChevalier, John Parks-Clifford (also known as “pc”), and Nora Tansky LeChevalier.

Nick Nicholas (NSN) would like to thank the following Lojbanists: Mark Shoulson, Veijo Vilva, Colin Fine, And Rosta, and Iain Alexander for their suggestions and comments; John Cowan, for his extensive comments, his exemplary trailblazing of Lojban grammar, and for solving the manskapi dilemma for NSN; Jorge Llambias, for his even more extensive comments, and for forcing NSN to think more than he was inclined to; Bob LeChevalier, for his skeptical overview of the issue, his encouragement, and for scouring all Lojban text his computer has been burdened with for lujvo; Nora Tansky LeChevalier, for writing the program converting old rafsi text to new rafsi text, and sparing NSN from embarrassing errors; and Jim Carter, for his dogged persistence in analyzing lujvo algorithmically, which inspired this research, and for first identifying the three lujvo classes.

Of course, the entire Loglan Project owes a considerable debt to James Cooke Brown as the language inventor, and also to several earlier contributors to the development of the language. Especially noteworthy are Doug Landauer, Jeff Prothero, Scott Layson, Jeff Taylor, and Bob McIvor. Final responsibility for the remaining errors and infelicities is solely mine.

The founding document for the Loglan Project, of which this book is one of the products, is Loglan 1: A Logical Language by James Cooke Brown (4th ed. 1989, The Loglan Institute, Gainesville, Florida, U.S.A.). The language described therein is not Lojban, but is very close to it and may be considered an ancestral version. It is regrettably necessary to state that nothing in this book has been approved by Dr. Brown, and that the very existence of Lojban is disapproved of by him.

The logic of Lojban, such as it is, owes a good deal to the American philosopher W. v.O. Quine, especially Word and Object (1960, M.I.T. Press). Much of Quine's philosophical writings, especially on observation sentences, reads like a literal translation from Lojban.

The theory of negation expounded in Chapter 15 is derived from a reading of Laurence Horn's work A Natural History of Negation.

Of course, neither Brown nor Quine nor Horn is in any way responsible for the uses or misuses I have made of their works.

Depending on just when you are reading this book, there may be three other books about Lojban available: a textbook, a Lojban/English dictionary, and a book containing general information about Lojban. You can probably get these books, if they have been published, from the same place where you got this book. In addition, other books not yet foreseen may also exist.

The following examples list the Lojban caption, with a translation, for the picture at the head of each chapter. If a chapter's picture has no caption, “(none)” is specified instead.

Copyright © 1997 by The Logical Language Group, Inc. All Rights Reserved.

Permission is granted to make and distribute verbatim copies of this book, either in electronic or in printed form, provided the copyright notice and this permission notice are preserved on all copies.

Permission is granted to copy and distribute modified versions of this book, provided that the modifications are clearly marked as such, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one.

Permission is granted to copy and distribute translations of this book into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation that has been approved by the Logical Language Group, rather than in English.

The contents of Chapter 21 are in the public domain.

For information, contact: The Logical Language Group, 2904 Beau Lane, Fairfax VA 22031-1303 USA. Telephone: 703-385-0273. Email address: llg-board@lojban.org. Web Address: http://www.lojban.org.

This chapter gives diagrammed examples of basic Lojban sentence structures. The most general pattern is covered first, followed by successive variations on the basic components of the Lojban sentence. There are many more capabilities not covered in this chapter, but covered in detail in later chapters, so this chapter is a “quick tour” of the material later covered more slowly throughout the book. It also introduces most of the Lojban words used to discuss Lojban grammar.

Let us consider John and Sam and three statements about them:

These examples all describe relationships between John and Sam. However, in English, we use the noun “father” to describe a static relationship in Example 2.1, the verb “hits” to describe an active relationship in Example 2.2, and the adjective “taller” to describe an attributive relationship in Example 2.3. In Lojban we make no such grammatical distinctions; these three sentences, when expressed in Lojban, are structurally identical. The same part of speech is used to represent the relationship. In formal logic this whole structure is called a “predication”; in Lojban it is called a bridi, and the central part of speech is the selbri. Logicians refer to the things thus related as “arguments”, while Lojbanists call them sumti. These Lojban terms will be used for the rest of the book.

In a relationship, there are a definite number of things being related. In English, for example, “give” has three places: the donor, the recipient and the gift. For example:

and

mean two different things because the relative positions of “John” and “Sam” have been switched. Further,

seems strange to us merely because the places are being filled by unorthodox arguments. The relationship expressed by “give” has not changed.

In Lojban, each selbri has a specified number and type of arguments, known collectively as its “place structure”. The simplest kind of selbri consists of a single root word, called a gismu, and the definition in a dictionary gives the place structure explicitly. The primary task of constructing a Lojban sentence, after choosing the relationship itself, is deciding what you will use to fill in the sumti places.

This book uses the Lojban terms bridi, sumti, and selbri, because it is best to come to understand them independently of the English associations of the corresponding words, which are only roughly similar in meaning anyhow.

The Lojban examples in this chapter (but not in the rest of the book) use boldface (as well as the usual italics) for selbri, to help you to tell them apart.

Detailed pronunciation and spelling rules are given in Chapter 3, but what follows will keep the reader from going too far astray while digesting this chapter.

Lojban has six recognized vowels: a, e, i, o, u and y. The first five are roughly pronounced as “a” as in “father”, e as in “let”, i as in “machine”, o as in “dome” and u as in “flute”. y is pronounced as the sound called “schwa”, that is, as the unstressed “a” as in “about” or “around”.

Twelve consonants in Lojban are pronounced more or less as their counterparts are in English: b, d, f, k, l, m, n, p, r, t, v and z. The letter c, on the other hand is pronounced as the “sh” in “hush”, while j is its voiced counterpart, the sound of the “s” in “pleasure”. g is always pronounced as it is in “gift”, never as in “giant”. s is as in “sell”, never as in “rose”. The sound of x is not found in English in normal words. It is found as “ch” in Scottish “loch”, as “j” in Spanish “junta”, and as „ch“ in German „Bach“; it also appears in the English interjection “yecchh!”. It gets easier to say as you practice it. The letter r can be trilled, but doesn't have to be.

The Lojban diphthongs ai, ei, oi, and au are pronounced much as in the English words “sigh”, “say”, “boy”, and “how”. Other Lojban diphthongs begin with an i pronounced like English “y” (for example, io is pronounced “yo”) or else with a u pronounced like English “w” (for example, ua is pronounced “wa”).

Lojban also has three “semi-letters”; the period, the comma and the apostrophe. The period represents a glottal stop or a pause; it is a required stoppage of the flow of air in the speech stream. The apostrophe sounds just like the English letter “h”. Unlike a regular consonant, it is not found at the beginning or end of a word, nor is it found adjacent to a consonant; it is only found between two vowels. The comma has no sound associated with it, and is used to separate syllables that might ordinarily run together. It is not used in this chapter.

Stress falls on the next to the last syllable of all words, unless that vowel is y, which is never stressed; in such words the third-to-last syllable is stressed. If a word only has one syllable, then that syllable is not stressed.

All Lojban words are pronounced as they are spelled: there are no silent letters.

Here is a short table of single words used as sumti. This table provides examples only, not the entire set of such words, which may be found in Section 7.16.

Lojban sumti are not specific as to number (singular or plural), nor gender (masculine/feminine/neutral). Such distinctions can be optionally added by methods that are beyond the scope of this chapter.

The cmavo ti, ta, and tu refer to whatever the speaker is pointing at, and should not be used to refer to things that cannot in principle be pointed at.

Names may also be used as sumti, provided they are preceded with the word la:

Other Lojban spelling versions are possible for names from other languages, and there are restrictions on which letters may appear in Lojban names: see Section 6.12 for more information.

Here is a short table of some words used as Lojban selbri in this chapter:

Each selbri (relation) has a specific rule that defines the role of each sumti in the bridi, based on its position. In the table above, that order was expressed by labeling the sumti positions as x₁, x₂, x₃, x₄, and x₅.

Like the table in Section 2.3, this table is far from complete: in fact, no complete table can exist, because Lojban allows new words to be created (in specified ways) whenever a speaker or writer finds the existing supply of words inadequate. This notion is a basic difference between Lojban (and some other languages such as German and Chinese) and English; in English, most people are very leery of using words that “aren't in the dictionary”. Lojbanists are encouraged to invent new words; doing so is a major way of participating in the development of the language. Chapter 4 explains how to make new words, and Chapter 12 explains how to give them appropriate meanings.

Let's look at a simple Lojban bridi. The place structure of the gismu tavla is

where the “x” es with following numbers represent the various arguments that could be inserted at the given positions in the English sentence. For example:

has “John” in the x₁ place, “Sam” in the x₂ place, “engineering” in the x₃ place, and “Lojban” in the x₄ place, and could be paraphrased:

The Lojban bridi corresponding to Example 2.7 will have the form

The word cu serves as a separator between any preceding sumti and the selbri. It can often be omitted, as in the following examples.

(In Example 2.13 the word ly. is a so-called letteral for the Lojban letter “l” and refers to something labelled “l”, most likely the language “Lojban” as its first letter is “l”).

When there are one or more occurrences of the cmavo zo'e at the end of a bridi, they may be omitted, a process called “ellipsis”. Example 2.11 and Example 2.12 may be expressed thus:

Note that Example 2.13 is not subject to ellipsis by this direct method, as the zo'e in it is not at the end of the bridi.

Consider the sentence

Example 2.16 has one sumti (the x₁) before the selbri. It is also possible to put more than one sumti before the selbri, without changing the order of sumti:

Example 2.16 through Example 2.18 mean the same thing. Usually, placing more than one sumti before the selbri is done for style or for emphasis on the sumti that are out-of-place from their normal position. (Native speakers of languages other than English may prefer such orders.)

If there are no sumti before the selbri, then it is understood that the x₁ sumti value is equivalent to zo'e; i.e. unimportant or obvious, and therefore not given. Any sumti after the selbri start counting from x₂.

when the x₁ is omitted, becomes:

Omitting the x₁ adds emphasis to the selbri relation, which has become first in the sentence. This kind of sentence is termed an observative, because it is often used when someone first observes or takes note of the relationship, and wishes to quickly communicate it to someone else. Commonly understood English observatives include “Smoke!” upon seeing smoke or smelling the odor, or “Car!” to a person crossing the street who might be in danger. Any Lojban selbri can be used as an observative if no sumti appear before the selbri.

The word cu does not occur in an observative; cu is a separator, and there must be a sumti before the selbri that needs to be kept separate for cu to be used. With no sumti preceding the selbri, cu is not permitted. Short words like cu which serve grammatical functions are called cmavo in Lojban.

For one reason or another you may want to change the order, placing one particular sumti at the front of the bridi. The cmavo se, when placed before the last word of the selbri, will switch the meanings of the first and second sumti places. So

has the same meaning as

The cmavo te, when used in the same location, switches the meanings of the first and the third sumti places.

has the same meaning as

Note that only the first and third sumti have switched places; the second sumti has remained in the second place.

The cmavo ve and xe switch the first and fourth sumti places, and the first and fifth sumti places, respectively. These changes in the order of places are known as “conversions”, and the se, te, ve, and xe cmavo are said to convert the selbri.

More than one of these operators may be used on a given selbri at one time, and in such a case they are evaluated from left to right. However, in practice they are used one at a time, as there are better tools for complex manipulation of the sumti places. See Section 9.4 for details.

The effect is similar to what in English is called the “passive voice”. In Lojban, the converted selbri has a new place structure that is renumbered to reflect the place reversal, thus having effects when such a conversion is used in combination with other constructs such as le selbri [ku] (see Section 2.10).

People don't always say just one sentence. Lojban has a specific structure for talk or writing that is longer than one sentence. The entirety of a given speech event or written text is called an utterance. The sentences (usually, but not always, bridi) in an utterance are separated by the cmavo ni'o and .i. These correspond to a brief pause (or nothing at all) in spoken English, and the various punctuation marks like period, question mark, and exclamation mark in written English. These separators prevent the sumti at the beginning of the next sentence from being mistaken for a trailing sumti of the previous sentence.

The cmavo ni'o separates paragraphs (covering different topics of discussion). In a long text or utterance, the topical structure of the text may be indicated by multiple ni'o s, with perhaps ni'oni'oni'o used to indicate a chapter, ni'oni'o to indicate a section, and a single ni'o to indicate a subtopic corresponding to a single English paragraph.

The cmavo .i separates sentences. It is sometimes compounded with words that modify the exact meaning (the semantics) of the sentence in the context of the utterance. (The cmavo xu, discussed in Section 2.15, is one such word – it turns the sentence from a statement to a question about truth.) When more than one person is talking, a new speaker will usually omit the .i even though she/he may be continuing on the same topic.

It is still O.K. for a new speaker to say the .i before continuing; indeed, it is encouraged for maximum clarity (since it is possible that the second speaker might merely be adding words onto the end of the first speaker's sentence). A good translation for .i is the “and” used in run-on sentences when people are talking informally: “I did this, and then I did that, and ..., and ...”.

When two gismu are adjacent, the first one modifies the second, and the selbri takes its place structure from the rightmost word. Such combinations of gismu are called tanru. For example,

has the place structure

When three or more gismu are in a row, the first modifies the second, and that combined meaning modifies the third, and that combined meaning modifies the fourth, and so on. For example

has the place structure

That is, it is a shoe that is worn by a fast talker rather than a shoe that is fast and is also worn by a talker.

Note especially the use of “type-of” as a mechanism for connecting the English translations of the two or more gismu; this convention helps the learner understand each tanru in its context. Creative interpretations are also possible, however:

most probably refers to shoes suitable for runners, but might be interpreted in some imaginative instances as “shoes that run (by themselves?)”. In general, however, the meaning of a tanru is determined by the literal meaning of its components, and not by any connotations or figurative meanings. Thus

would not necessarily imply any trickery or deception, unlike the English idiom, and a

must always be a moth or a butterfly.

The place structure of a tanru is always that of the final component of the tanru. Thus, the following has the place structure of klama:

With the conversion se klama as the final component of the tanru, the place structure of the entire selbri is that of se klama: the x₁ place is the destination, and the x₂ place is the one who goes:

The following example shows that there is more to conversion than merely switching places, though:

has the place structure of tavla, but note the two distinct interpretations.

Now, using conversion, we can modify the place structure order:

and we see that the modification has been changed so as to focus on Mary's role in the bridi relationship, leading to a different set of possible interpretations.

Note that there is no place structure change if the modifying term is converted, and so less drastic variation in possible meanings:

and we see that the manner in which Tom is seen as beautiful by Mary changes, but Tom is still the one perceived as beautiful, and Mary, the observer of beauty.

Often we wish to talk about things other than the speaker, the listener and things we can point to. Let's say I want to talk about a talker other than mi. What I want to talk about would naturally fit into the first place of tavla. Lojban, it turns out, has an operator that pulls this first place out of a selbri and converts it to a sumti called a “description sumti”. The description sumti le tavla ku means “the talker”, and may be used wherever any sumti may be used.

For example,

means the same as

where “the talker” is presumably someone other than me, though not necessarily.

Similarly le sutra tavla ku is “the fast talker”, and le sutra te tavla ku is “the fast subject of talk” or “the subject of fast talk”. Which of these related meanings is understood will depend on the context in which the expression is used. The most plausible interpretation within the context will generally be assumed by a listener to be the intended one.

In many cases the word ku may be omitted. In particular, it is never necessary in a description at the end of a sentence, so:

means exactly the same thing as Example 2.38.

There is a problem when we want to say “The fast one is talking.” The “obvious” translation le sutra tavla turns out to mean “the fast talker”, and has no selbri at all. To solve this problem we can use the word cu, which so far has always been optional, in front of the selbri.

The word cu has no meaning, and exists only to mark the beginning of the selbri within the bridi, separating it from a previous sumti. It comes before any other part of the selbri, including other cmavo like se or te. Thus:

Consider the following more complex example, with two description sumti.

The sumti le vecnu contains the selbri vecnu, which has the “seller” in the x₁ place, and uses it in this sentence to describe a particular “seller” that the speaker has in mind (one that he or she probably expects the listener will also know about). Similarly, the speaker has a particular blue-green thing in mind, which is described using le to mark blari'o, a selbri whose first sumti is something blue-green.

It is safe to omit both occurrences of ku in Example 2.45, and it is also safe to omit the cu.

The simplest form of selbri is an individual word. A word which may by itself express a selbri relation is called a brivla. The three types of brivla are gismu (root words), lujvo (compounds), and fu'ivla (borrowings from other languages). All have identical grammatical uses. So far, most of our selbri have been gismu or tanru built from gismu.

gismu:

lujvo:

fu'ivla:

Some cmavo may also serve as selbri, acting as variables that stand for another selbri. The most commonly used of these is go'i, which represents the main bridi of the previous Lojban sentence, with any new sumti or other sentence features being expressed replacing the previously expressed ones. Thus, in this context:

In English, I might say “The dog is beautiful”, and you might reply “This pleases me.” How do you know what “this” refers to? Lojban uses different expressions to convey the possible meanings of the English:

The following three sentences all might translate as “This pleases me.”

Example 2.53 uses one sumti to point to or refer to another by inference. It is common to write la'edi'u as a single word; it is used more often than di'u by itself.

“Possession” refers to the concept of specifying an object by saying who it belongs to (or with). A full explanation of Lojban possession is given in Chapter 8. A simple means of expressing possession, however, is to place a sumti representing the possessor of an object within the description sumti that refers to the object: specifically, between the le and the selbri of the description:

In Lojban, possession doesn't necessarily mean ownership: one may “possess” a chair simply by sitting on it, even though it actually belongs to someone else. English uses possession casually in the same way, but also uses it to refer to actual ownership or even more intimate relationships: “my arm” doesn't mean “some arm I own” but rather “the arm that is part of my body”. Lojban has methods of specifying all these different kinds of possession precisely and easily.

You may call someone's attention to the fact that you are addressing them by using doi followed by their name. The sentence

means “Oh, John, I'm talking to you”. It also has the effect of setting the value of do; do now refers to “John” until it is changed in some way in the conversation. Note that Example 2.55 is not a bridi, but it is a legitimate Lojban sentence nevertheless; it is known as a “vocative phrase”.

Other cmavo can be used instead of doi in a vocative phrase, with a different significance. For example, the cmavo coi means “hello” and co'o means “good-bye”. Either word may stand alone, they may follow one another, or either may be followed by a Lojbanized name surrounded by pauses.

Commands are expressed in Lojban by a simple variation of the main bridi structure. If you say

you are simply making a statement of fact. In order to issue a command in Lojban, substitute the word ko for do. The bridi

instructs the listener to do whatever is necessary to make Example 2.58 true; it means “Talk!” Other examples:

The ko need not be in the x₁ place, but rather can occur anywhere a sumti is allowed, leading to possible Lojban commands that are very unlike English commands:

The cmavo ko can fill any appropriate sumti place, and can be used as often as is appropriate for the selbri:

and

both mean “You take care of you” and “Be taken care of by you”, or to put it colloquially, “Take care of yourself”.

There are many kinds of questions in Lojban: full explanations appear in Section 19.5 and in various other chapters throughout the book. In this chapter, we will introduce three kinds: sumti questions, selbri questions, and yes/no questions.

The cmavo ma is used to create a sumti question: it indicates that the speaker wishes to know the sumti which should be placed at the location of the ma to make the bridi true. It can be translated as “Who?” or “What?” in most cases, but also serves for “When?”, “Where?”, and “Why?” when used in sumti places that express time, location, or cause. For example:

The listener can reply by simply stating a sumti:

Like ko, ma can occur in any position where a sumti is allowed, not just in the first position:

A ma can also appear in multiple sumti positions in one sentence, in effect asking several questions at once.

The two separate ma positions ask two separate questions, and can therefore be answered with different values in each sumti place.

The cmavo mo is the selbri analogue of ma. It asks the respondent to provide a selbri that would be a true relation if inserted in place of the mo:

A mo may be used anywhere a brivla or other selbri might. Keep this in mind for later examples. Unfortunately, by itself, mo is a very non-specific question. The response to the question in Example 2.68 could be:

or:

Clearly, mo requires some cooperation between the speaker and the respondent to ensure that the right question is being answered. If context doesn't make the question specific enough, the speaker must ask the question more specifically using a more complex construction such as a tanru (see Section 2.9).

It is perfectly permissible for the respondent to fill in other unspecified places in responding to a mo question. Thus, the respondent in Example 2.70 could have also specified an audience, a topic, and/or a language in the response.

Finally, we must consider questions that can be answered “Yes” or “No”, such as

Like all yes-or-no questions in English, Example 2.71 may be reformulated as

In Lojban we have a word that asks precisely that question in precisely the same way. The cmavo xu, when placed in front of a bridi, asks whether that bridi is true as stated. So

is the Lojban translation of Example 2.71.

The answer “Yes” may be given by simply restating the bridi without the xu question word. Lojban has a shorthand for doing this with the word go'i, mentioned in Section 2.11. Instead of a negative answer, the bridi may be restated in such a way as to make it true. If this can be done by substituting sumti, it may be done with go'i as well. For example:

can be answered with

or

(Note that do to the questioner is mi to the respondent.)

or

or

A general negative answer may be given by na go'i. na may be placed before any selbri (but after the cu). It is equivalent to stating “It is not true that ...” before the bridi. It does not imply that anything else is true or untrue, only that that specific bridi is not true. More details on negative statements are available in Chapter 15.

Different cultures express emotions and attitudes with a variety of intonations and gestures that are not usually included in written language. Some of these are available in some languages as interjections (i.e. “Aha!”, “Oh no!”, “Ouch!”, “Aahh!”, etc.), but they vary greatly from culture to culture.

Lojban has a group of cmavo known as “attitudinal indicators” which specifically covers this type of commentary on spoken statements. They are both written and spoken, but require no specific intonation or gestures. Grammatically they are very simple: one or more attitudinals at the beginning of a bridi apply to the entire bridi; anywhere else in the bridi they apply to the word immediately to the left. For example:

Not all indicators indicate attitudes. Discursives, another group of cmavo with the same grammatical rules as attitudinal indicators, allow free expression of certain kinds of commentary about the main utterances. Using discursives allows a clear separation of these so-called “metalinguistic” features from the underlying statements and logical structure. By comparison, the English words “but” and “also”, which discursively indicate contrast or an added weight of example, are logically equivalent to “and”, which does not have a discursive content. The average English-speaker does not think about, and may not even realize, the paradoxical idea that “but” basically means “and”.

Another group of indicators are called “evidentials”. Evidentials show the speaker's relationship to the statement, specifically how the speaker came to make the statement. These include za'a (I directly observe the relationship), pe'i (I believe that the relationship holds), ru'a (I postulate the relationship), and others. Many American Indian languages use this kind of words.

In English, every verb is tagged for the grammatical category called tense: past, present, or future. The sentence

necessarily happens at some time in the past, whereas

is necessarily happening right now.

The Lojban sentence

serves as a translation of either Example 2.87 or Example 2.88, and of many other possible English sentences as well. It is not marked for tense, and can refer to an event in the past, the present or the future. This rule does not mean that Lojban has no way of representing the time of an event. A close translation of Example 2.87 would be:

where the tag pu forces the sentence to refer to a time in the past. Similarly,

necessarily refers to the present, because of the tag ca. Tags used in this way always appear at the very beginning of the selbri, just after the cu, and they may make a cu unnecessary, since tags cannot be absorbed into tanru. Such tags serve as an equivalent to English tenses and adverbs. In Lojban, tense information is completely optional. If unspecified, the appropriate tense is picked up from context.

Lojban also extends the notion of “tense” to refer not only to time but to space. The following example uses the tag vu to specify that the event it describes happens far away from the speaker:

In addition, tense tags (either for time or space) can be prefixed to the selbri of a description, producing a tensed sumti:

(Since Lojban tense is optional, we don't know when he or she talks.)

Tensed sumti with space tags correspond roughly to the English use of “this” or “that” as adjectives, as in the following example, which uses the tag vi meaning “nearby”:

Do not confuse the use of vi in Example 2.94 with the cmavo ti, which also means “this”, but in the sense of “this thing”.

Furthermore, a tense tag can appear both on the selbri and within a description, as in the following example (where ba is the tag for future time):

Here is a review of the Lojban grammatical terms used in this chapter, plus some others used throughout this book. Only terms that are themselves Lojban words are included: there are of course many expressions like “indicator” in Chapter 16 that are not explained here. See the Index for further help with these.

Lojban is designed so that any properly spoken Lojban utterance can be uniquely transcribed in writing, and any properly written Lojban can be spoken so as to be uniquely reproduced by another person. As a consequence, the standard Lojban orthography must assign to each distinct sound, or phoneme, a unique letter or symbol. Each letter or symbol has only one sound or, more accurately, a limited range of sounds that are permitted pronunciations for that phoneme. Some symbols indicate stress (speech emphasis) and pause, which are also essential to Lojban word recognition. In addition, everything that is represented in other languages by punctuation (when written) or by tone of voice (when spoken) is represented in Lojban by words. These two properties together are known technically as “audio-visual isomorphism”.

Lojban uses a variant of the Latin (Roman) alphabet, consisting of the following letters and symbols:

'

,

.

a

b

c

d

e

f

g

i

j

k

l

m

n

o

p

r

s

t

u

v

x

y

z

omitting the letters “h” , “q” , and “w”.

The alphabetic order given above is that of the ASCII coded character set, widely used in computers. By making Lojban alphabetical order the same as ASCII, computerized sorting and searching of Lojban text is facilitated.

Capital letters are used only to represent non-standard stress, which can appear only in the representation of Lojbanized names. Thus the English name “Josephine” , as normally pronounced, is Lojbanized as .DJOsefin. , pronounced ['ʔdʒosɛfinʔ]. (See Section 3.2 for an explanation of the symbols within square brackets.) Technically, it is sufficient to capitalize the vowel letter, in this case O , but it is easier on the reader to capitalize the whole syllable.

Without the capitalization, the ordinary rules of Lojban stress would cause the se syllable to be stressed. Lojbanized names are meant to represent the pronunciation of names from other languages with as little distortion as may be; as such, they are exempt from many of the regular rules of Lojban phonology, as will appear in the rest of this chapter.

Lojban pronunciations are defined using the International Phonetic Alphabet, or IPA, a standard method of transcribing pronunciations. By convention, IPA transcriptions are always within square brackets: for example, the word “cat” is pronounced (in General American pronunciation) [kæt]. Section 3.10 contains a brief explanation of the IPA characters used in this chapter, with their nearest analogues in English, and will be especially useful to those not familiar with the technical terms used in describing speech sounds.

The standard pronunciations and permitted variants of the Lojban letters are listed in the table below. The descriptions have deliberately been made a bit ambiguous to cover variations in pronunciation by speakers of different native languages and dialects. In all cases except r the first IPA symbol shown represents the preferred pronunciation; for r , all of the variations (and any other rhotic sound) are equally acceptable.

The Lojban sounds must be clearly pronounced so that they are not mistaken for each other. Voicing and placement of the tongue are the key factors in correct pronunciation, but other subtle differences will develop between consonants in a Lojban-speaking community. At this point these are the only mandatory rules on the range of sounds.

Note in particular that Lojban vowels can be pronounced with either rounded or unrounded lips; typically o and u are rounded and the others are not, as in English, but this is not a requirement; some people round y as well. Lojban consonants can be aspirated or unaspirated. Palatalizing of consonants, as found in Russian and other languages, is not generally acceptable in pronunciation, though a following i may cause it.

The sounds represented by the letters c , g , j , s , and x require special attention for speakers of English, either because they are ambiguous in the orthography of English ( c , g , s), or because they are strikingly different in Lojban ( c , j , x). The English “c” represents three different sounds, [k] in “cat” and [s] in “cent” , as well as the [ʃ] of “ocean”. Similarly, English “g” can represent [ɡ] as in “go” , [dʒ] as in “gentle” , and [ʒ] as in the second "g" in “garage” (in some pronunciations). English “s” can be either [s] as in “cats” , [z] as in “cards” , [ʃ] as in “tension” , or [ʒ] as in “measure”. The sound of Lojban x doesn't appear in most English dialects at all.

There are two common English sounds that are found in Lojban but are not Lojban consonants: the “ch” of “church” and the “j” of “judge”. In Lojban, these are considered two consonant sounds spoken together without an intervening vowel sound, and so are represented in Lojban by the two separate consonants: tc (IPA [tʃ]) and dj (IPA [dʒ]). In general, whether a complex sound is considered one sound or two depends on the language: Russian views “ts” as a single sound, whereas English, French, and Lojban consider it to be a consonant cluster.

The apostrophe, period, and comma need special attention. They are all used as indicators of a division between syllables, but each has a different pronunciation, and each is used for different reasons:

The apostrophe represents a phoneme similar to a short, breathy English “h” , (IPA [h]). The letter “h” is not used to represent this sound for two reasons: primarily in order to simplify explanations of the morphology, but also because the sound is very common, and the apostrophe is a visually lightweight representation of it. The apostrophe sound is a consonant in nature, but is not treated as either a consonant or a vowel for purposes of Lojban morphology (word-formation), which is explained in Chapter 4. In addition, the apostrophe visually parallels the comma and the period, which are also used (in different ways) to separate syllables.

The apostrophe is included in Lojban only to enable a smooth transition between vowels, while joining the vowels within a single word. In fact, one way to think of the apostrophe is as representing an unvoiced vowel glide.

As a permitted variant, any unvoiced fricative other than those already used in Lojban may be used to render the apostrophe: IPA [θ] is one possibility. The convenience of the listener should be regarded as paramount in deciding to use a substitute for [h].

The period represents a mandatory pause, with no specified length; a glottal stop (IPA [ʔ]) is considered a pause of shortest length. A pause (or glottal stop) may appear between any two words, and in certain cases – explained in detail in Section 4.9 – must occur. In particular, a word beginning with a vowel is always preceded by a pause, and a word ending in a consonant is always surrounded by pauses.

Technically, the period is an optional reminder to the reader of a mandatory pause that is dictated by the rules of the language; because these rules are unambiguous, a missing period can be inferred from otherwise correct text. Periods are included only as an aid to the reader.

A period also may be found apparently embedded in a word. When this occurs, such a written string is not one word but two, written together to indicate that the writer intends a unitary meaning for the compound. It is not really necessary to use a space between words if a period appears.

The comma is used to indicate a syllable break within a word, generally one that is not obvious to the reader. Such a comma is written to separate syllables, but indicates that there must be no pause between them, in contrast to the period. Between two vowels, a comma indicates that some type of glide may be necessary to avoid a pause that would split the two syllables into separate words. It is always legal to use the apostrophe (IPA [h]) sound in pronouncing a comma. However, a comma cannot be pronounced as a pause or glottal stop between the two letters separated by the comma, because that pronunciation would split the word into two words.

Otherwise, a comma is usually only used to clarify the presence of syllabic l , m , n , or r (discussed later). Commas are never required: no two Lojban words differ solely because of the presence or placement of a comma.

Here is a somewhat artificial example of the difference in pronunciation between periods, commas and apostrophes. In the English song about Old MacDonald's Farm, the vowel string which is written as “ee-i-ee-i-o” in English could be Lojbanized with periods as:

However, this would sound clipped, staccato, and unmusical compared to the English. Furthermore, although Example 3.1 is a string of meaningful Lojban words, as a sentence it makes very little sense. (Note the use of periods embedded within the written word.)

If commas were used instead of periods, we could represent the English string as a Lojbanized name, ending in a consonant:

The commas represent new syllable breaks, but prohibit the use of pauses or glottal stop. The pronunciation shown is just one possibility, but closely parallels the intended English pronunciation.

However, the use of commas in this way is risky to unambiguous interpretation, since the glides might be heard by some listeners as diphthongs, producing something like

which is technically a different Lojban name. Since the intent with Lojbanized names is to allow them to be pronounced more like their native counterparts, the comma is allowed to represent vowel glides or some non-Lojbanic sound. Such an exception affects only spelling accuracy and the ability of a reader to replicate the desired pronunciation exactly; it will not affect the recognition of word boundaries.

Still, it is better if Lojbanized names are always distinct. Therefore, the apostrophe is preferred in regular Lojbanized names that are not attempting to simulate a non-Lojban pronunciation perfectly. (Perfection, in any event, is not really achievable, because some sounds simply lack reasonable Lojbanic counterparts.)

If apostrophes were used instead of commas in Example 3.2 , it would appear as:

which preserves the rhythm and length, if not the exact sounds, of the original English.

There exist 16 diphthongs in the Lojban language. A diphthong is a vowel sound that consists of two elements, a short vowel sound and a glide, either a labial (IPA [w]) or palatal (IPA [j]) glide, that either precedes (an on-glide) or follows (an off-glide) the main vowel. Diphthongs always constitute a single syllable.

For Lojban purposes, a vowel sound is a relatively long speech-sound that forms the nucleus of a syllable. Consonant sounds are relatively brief and normally require an accompanying vowel sound in order to be audible. Consonants may occur at the beginning or end of a syllable, around the vowel, and there may be several consonants in a cluster in either position. Each separate vowel sound constitutes a distinct syllable; consonant sounds do not affect the determination of syllables.

The six Lojban vowels are a , e , i , o , u , and y. The first five vowels appear freely in all kinds of Lojban words. The vowel y has a limited distribution: it appears only in Lojbanized names, in the Lojban names of the letters of the alphabet, as a glue vowel in compound words, and standing alone as a space-filler word (like English “uh” or “er”).

The Lojban diphthongs are shown in the table below. (Variant pronunciations have been omitted, but are much as one would expect based on the variant pronunciations of the separate vowel letters: ai may be pronounced [ɑj] , for example.)

(Approximate English equivalents of most of these diphthongs exist: see Section 3.11 for examples.)

The first four diphthongs above ( ai , ei , oi , and au , the ones with off-glides) are freely used in most types of Lojban words; the ten following ones are used only as stand-alone words and in Lojbanized names and borrowings; and the last two ( iy and uy) are used only in Lojbanized names.

The syllabic consonants of Lojban, [l̩] , [m̩] , [n̩] , and [r̩] , are variants of the non-syllabic [l] , [m] , [n] , and [r] respectively. They normally have only a limited distribution, appearing in Lojbanized names and borrowings, although in principle any l , m , n , or r may be pronounced syllabically. If a syllabic consonant appears next to a l , m , n , or r that is not syllabic, it may not be clear which is which:

is a hypothetical Lojbanized name with more than one valid pronunciation; however it is pronounced, it remains the same word.

Syllabic consonants are treated as consonants rather than vowels from the standpoint of Lojban morphology. Thus Lojbanized names, which are generally required to end in a consonant, are allowed to end with a syllabic consonant. An example is .rl. , which is an approximation of the English name “Earl” , and has two syllabic consonants.

Syllables with syllabic consonants and no vowel are never stressed or counted when determining which syllables to stress (see Section 3.9).

Lojban vowels also occur in pairs, where each vowel sound is in a separate syllable. These two vowel sounds are connected (and separated) by an apostrophe. Lojban vowel pairs should be pronounced continuously with the [h] sound between (and not by a glottal stop or pause, which would split the two vowels into separate words).

All vowel combinations are permitted in two-syllable pairs with the apostrophe separating them; this includes those which constitute diphthongs when the apostrophe is not included.

The Lojban vowel pairs are:

a'a	a'e	a'i	a'o	a'u	a'y
e'a	e'e	e'i	e'o	e'u	e'y
i'a	i'e	i'i	i'o	i'u	i'y
o'a	o'e	o'i	o'o	o'u	o'y
u'a	u'e	u'i	u'o	u'u	u'y
y'a	y'e	y'i	y'o	y'u	y'y

Vowel pairs involving y appear only in Lojbanized names. They could appear in cmavo (structure words), but only .y'y. is so used – it is the Lojban name of the apostrophe letter (see Section 17.2).

When more than two vowels occur together in Lojban, the normal pronunciation pairs vowels from the left into syllables, as in the Lojbanized name:

Example 3.6 contains the diphthong ei followed by the vowel i. In order to indicate a different grouping, the comma must always be used, leading to:

which contains the vowel e followed by the diphthong ii. In rough English representation, Example 3.6 is “May Een” , whereas Example 3.7 is “Meh Yeen”.

A consonant sound is a relatively brief speech-sound that precedes or follows a vowel sound in a syllable; its presence either preceding or following does not add to the count of syllables, nor is a consonant required in either position for any syllable. Lojban has seventeen consonants: for the purposes of this section, the apostrophe is not counted as a consonant.

An important distinction dividing Lojban consonants is that of voicing. The following table shows the unvoiced consonants and the corresponding voiced ones:

The consonant x has no voiced counterpart in Lojban. The remaining consonants, l , m , n , and r , are typically pronounced with voice, but can be pronounced unvoiced.

Consonant sounds occur in languages as single consonants, or as doubled, or as clustered combinations. Single consonant sounds are isolated by word boundaries or by intervening vowel sounds from other consonant sounds. Doubled consonant sounds are either lengthened like [s] in English “hiss” , or repeated like [k] in English “backcourt”. Consonant clusters consist of two or more single or doubled consonant sounds in a group, each of which is different from its immediate neighbor. In Lojban, doubled consonants are excluded altogether, and clusters are limited to two or three members, except in Lojbanized names.

Consonants can occur in three positions in words: initial (at the beginning), medial (in the middle), and final (at the end). In many languages, the sound of a consonant varies depending upon its position in the word. In Lojban, as much as possible, the sound of a consonant is unrelated to its position. In particular, the common American English trait of changing a “t” between vowels into a “d” or even an alveolar tap (IPA [ɾ]) is unacceptable in Lojban.

Lojban imposes no restrictions on the appearance of single consonants in any valid consonant position; however, no consonant (including syllabic consonants) occurs final in a word except in Lojbanized names.

Pairs of consonants can also appear freely, with the following restrictions:

These rules apply to all kinds of words, even Lojbanized names. If a name would normally contain a forbidden consonant pair, a y can be inserted to break up the pair:

The regular English pronunciation of “James” , which is [dʒɛjmz] , would Lojbanize as .djeimz. , which contains a forbidden consonant pair.

The set of consonant pairs that may appear at the beginning of a word (excluding Lojbanized names) is far more restricted than the fairly large group of permissible consonant pairs described in Section 3.6. Even so, it is more than English allows, although hopefully not more than English-speakers (and others) can learn to pronounce.

There are just 48 such permissible initial consonant pairs, as follows:

Lest this list seem almost random, a pairing of voiced and unvoiced equivalent consonants will show significant patterns which may help in learning:

Note that if both consonants of an initial pair are voiced, the unvoiced equivalent is also permissible, and the voiced pair can be pronounced simply by voicing the unvoiced pair. (The converse is not true: cn is a permissible initial pair, but jn is not.)

Consonant triples can occur medially in Lojban words. They are subject to the following rules:

Lojbanized names can begin or end with any permissible consonant pair, not just the 48 initial consonant pairs listed above, and can have consonant triples in any location, as long as the pairs making up those triples are permissible. In addition, Lojbanized names can contain consonant clusters with more than three consonants, again requiring that each pair within the cluster is valid.

Many languages do not have consonant clusters at all, and even those languages that do have them often allow only a subset of the full Lojban set. As a result, the Lojban design allows the use of a buffer sound between consonant combinations which a speaker finds unpronounceable. This sound may be any non-Lojbanic vowel which is clearly separable by the listener from the Lojban vowels. Some possibilities are IPA [ɪ] , [ɨ] , [ʊ] , or even [ʏ] , but there probably is no universally acceptable buffer sound. When using a consonant buffer, the sound should be made as short as possible. Two examples showing such buffering (we will use [ɪ] in this chapter) are:

When a buffer vowel is used, it splits each buffered consonant into its own syllable. However, the buffering syllables are never stressed, and are not counted in determining stress. They are, in effect, not really syllables to a Lojban listener, and thus their impact is ignored.

Here are more examples of unbuffered and buffered pronunciations:

In Example 3.12 , we see that buffering vowels can be used in just some, rather than all, of the possible places: the second pronunciation buffers the pc consonant pair but not the ck. The third pronunciation buffers both.

Example 3.13 cannot contain any buffering vowel. It is important not to confuse the vowel y , which is pronounced [ə] , with the buffer, which has a variety of possible pronunciations and is never written. Consider the contrast between

an unlikely Lojban compound word meaning “bone bread” (note the use of [ŋ] as a representative of n before g) and

a possible borrowing from another language (Lojban borrowings can only take a limited form). If Example 3.15 were pronounced with buffering, as

it would be very similar to Example 3.14. Only a clear distinction between y and any buffering vowel would keep the two words distinct.

Since buffering is done for the benefit of the speaker in order to aid pronounceability, there is no guarantee that the listener will not mistake a buffer vowel for one of the six regular Lojban vowels. The buffer vowel should be as laxly pronounced as possible, as central as possible, and as short as possible. Furthermore, it is worthwhile for speakers who use buffers to pronounce their regular vowels a bit longer than usual, to avoid confusion with buffer vowels. The speakers of many languages will have trouble correctly hearing any of the suggested buffer vowels otherwise. By this guideline, Example 3.16 would be pronounced

with lengthened vowels.

A Lojban word has one syllable for each of its vowels, diphthongs, and syllabic consonants (referred to simply as “vowels” for the purposes of this section). Syllabication rules determine which of the consonants separating two vowels belong to the preceding vowel and which to the following vowel. These rules are conventional only; the phonetic facts of the matter about how utterances are syllabified in any language are always very complex.

A single consonant always belongs to the following vowel. A consonant pair is normally divided between the two vowels; however, if the pair constitute a valid initial consonant pair, they are normally both assigned to the following vowel. A consonant triple is divided between the first and second consonants. Apostrophes and commas, of course, also represent syllable breaks. Syllabic consonants usually appear alone in their syllables.

It is permissible to vary from these rules in Lojbanized names. For example, there are no definitive rules for the syllabication of Lojbanized names with consonant clusters longer than three consonants. The comma is used to indicate variant syllabication or to explicitly mark normal syllabication.

Here are some examples of Lojban syllabication:

This word has no consonant pairs and is therefore syllabified before each medial consonant.

This word is split at a consonant pair.

This word is split at a consonant triple, between the first two consonants of the triple.

This word contains the consonant pair rg ; the r may be pronounced syllabically or not.

This word contains the permissible initial pair zb , and so may be syllabicated either between z and b or before zb.

Stress is a relatively louder pronunciation of one syllable in a word or group of words. Since every syllable has a vowel sound (or diphthong or syllabic consonant) as its nucleus, and the stress is on the vowel sound itself, the terms “stressed syllable” and “stressed vowel” are largely interchangeable concepts.

Most Lojban words are stressed on the next-to-the-last, or penultimate, syllable. In counting syllables, however, syllables whose vowel is y or which contain a syllabic consonant ( l , m , n , or r) are never counted. (The Lojban term for penultimate stress is da'amoi terbasna.) Similarly, syllables created solely by adding a buffer vowel, such as [ɪ] , are not counted.

There are actually three levels of stress – primary, secondary, and weak. Weak stress is the lowest level, so it really means no stress at all. Weak stress is required for syllables containing y , a syllabic consonant, or a buffer vowel.

Primary stress is required on the penultimate syllable of Lojban content words (called brivla). Lojbanized names (called cmevla) may be stressed on any syllable, but if a syllable other than the penultimate is stressed, the syllable (or at least its vowel) must be capitalized in writing. Lojban structural words (called cmavo) may be stressed on any syllable or none at all. However, primary stress may not be used in a syllable just preceding a brivla, unless a pause divides them; otherwise, the two words may run together.

Secondary stress is the optional and non-distinctive emphasis used for other syllables besides those required to have either weak or primary stress. There are few rules governing secondary stress, which typically will follow a speaker's native language habits or preferences. Secondary stress can be used for contrast, or for emphasis of a point. Secondary stress can be emphasized at any level up to primary stress, although the speaker must not allow a false primary stress in brivla, since errors in word resolution could result.

The following are Lojban words with stress explicitly shown:

(In a fully-buffered dialect, the pronunciation would be: ['di kə ʒɪ vo].) Note that the syllable ky. is not counted in determining stress. The vowel y is never stressed in a normal Lojban context.

This is a Lojbanized version of the name “Armstrong”. The final g must be explicitly pronounced. With full buffering, the name would be pronounced:

However, there is no need to insert a buffer in every possible place just because it is inserted in one place: partial buffering is also acceptable. In every case, however, the stress remains in the same place: on the first syllable.

The English pronunciation of “Armstrong” , as spelled in English, is not correct by Lojban standards; the letters “ng” in English represent a velar nasal (IPA [ŋ]) which is a single consonant. In Lojban, ng represents two separate consonants that must both be pronounced; you may not use [ŋ] to pronounce Lojban ng , although [ŋg] is acceptable. English speakers are likely to have to pronounce the ending with a buffer, as one of the following:

The normal English pronunciation of the name “Armstrong” could be Lojbanized as:

since Lojban n is allowed to be pronounced as the velar nasal [ŋ].

Here is another example showing the use of y :

This word is a compound word, or lujvo, built from the two affixes bis and dja. When they are joined, an impermissible consonant pair results: sd. In accordance with the algorithm for making lujvo, explained in Section 4.11 , a y is inserted to separate the impermissible consonant pair; the y is not counted as a syllable for purposes of stress determination.

These two syllabications sound the same to a Lojban listener – the association of unbuffered consonants in syllables is of no import in recognizing the word.

In Example 3.30 , .e'u is a cmavo and bridi is a brivla. Either of the first two pronunciations is permitted: no primary stress on either syllable of .e'u , or primary stress on the first syllable. The third pronunciation, which places primary stress on the second syllable of the cmavo, requires that – since the following word is a brivla – the two words must be separated by a pause. Consider the following two cases:

If the cmavo no in Example 3.32 were to be stressed, the phrase would sound exactly like the given pronunciation of Example 3.31 , which is unacceptable in Lojban: a single pronunciation cannot represent both.

There are many dialects of English, thus making it difficult to define the standardized symbols of the IPA in terms useful to every reader. All the symbols used in this chapter are repeated here, in more or less alphabetical order, with examples drawn from General American. In addition, some attention is given to the Received Pronunciation of (British) English. These two dialects are referred to as GA and RP respectively. Speakers of other dialects should consult a book on phonetics or their local television sets.

The following guide will help American English speakers approximate Lojban sounds using familiar reference points from their dialect. When speaking Lojban, aim to pronounce each sound clearly and distinctly. Avoid the tendency in American English to reduce unstressed vowels to schwa or to add glides to pure vowels. Practice each sound individually and in combination to improve your Lojban pronunciation.

The following table is tailored for speakers of British English, particularly those familiar with Received Pronunciation (RP). While Lojban has a standardised pronunciation, some sounds may be challenging for RP speakers. This guide aims to clarify these differences and provide familiar reference points.

Note that Lojban consonants not listed here are pronounced similarly to their RP counterparts. RP speakers should be particularly mindful of the following: