Gismu

When two gismu are adjacent, the first one modifies the second, and the selbri takes its place structure from the rightmost word.

There are over 1,300 root gismu in the Lojban vocabulary, and these structures form a very interesting ontology of their own.

The main type of word used as a selbri is a gismu, or root-word. Each gismu is exactly five letters long, and has one of two consonant-vowel patterns:CVCCV or CCVCV (e.g. rafsi or bridi). The gismu are built so as to minimize listening errors in a noisy environment. A gismu has at least two combining forms, known as rafsi. One is the gismu itself; one is the gismu with the final vowel deleted. Certain gismu have additional, shorter rafsi assigned. Up to three of these shorter rafsi may be assigned to a gismu, depending on frequency of usage of the gismu in building complex concepts and on availability of these shorter rafsi. Short rafsi use only certain combinations of letters from the gismu, and are of the forms CCV, CVC, CVV or CV'V.