Chapter 2. A Quick Tour of Lojban Grammar, With Diagrams

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.

(Example 2.13 is a bit unusual, as there is no easy way to point to a language; one might point to a copy of this book, and hope the meaning gets across!)

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 an insect with large brightly-colored wings, of the family Lepidoptera.

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 pause and a name. (Vocative phrases with doi do not need a pause before the name.)

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.