4.3. brivla

Predicate words, called brivla, are at the core of Lojban. They carry most of the semantic information in the language. They serve as the equivalent of English nouns, verbs, adjectives, and adverbs, all in a single part of speech.

Every brivla belongs to one of three major subtypes. These subtypes are defined by the form, or morphology, of the word – all words of a particular structure can be assigned by sight or sound to a particular type (cmavo, brivla, or cmevla) and subtype. Knowing the type and subtype then gives you, the reader or listener, significant clues to the meaning and the origin of the word, even if you have never heard the word before.

The same principle allows you, when speaking or writing, to invent new brivla for new concepts on the fly; yet it offers people that you are trying to communicate with a good chance to figure out your meaning. In this way, Lojban has a flexible vocabulary which can be expanded indefinitely.

All brivla have the following properties: they

  1. always end in a vowel;

  2. contain a consonant cluster, or start with a CVCy string;

  3. and are always stressed on the next-to-the-last (penultimate) syllable; this implies that they have two or more syllables.

The presence of a consonant pair distinguishes brivla from cmavo. The final vowel distinguishes brivla from cmevla, which always end in a consonant. Thus da'amei must be a string of cmavo because it lacks a consonant pair; .lojban. must be a name because it lacks a final vowel.

The three subtypes of brivla are:

  1. gismu, the Lojban primitive roots from which other brivla are built;

  2. lujvo, the compounds of two or more gismu; and

  3. zi'evla (literally free-word), the words that are not Lojban primitives or natural compounds, and are often borrowed from other languages.