gerna -gen-ge'a- gismu

x1 is the grammar/rules/defining form of language x2 for structure/text x3.

See also bangu, stura, cmavo, jufra.

In notes:

bangu
x1 is a/the language/dialect used by x2 to express/communicate x3 (si'o/du'u, not quote).
cmavo
x1 is a structure word of grammatical class x2, with meaning/function x3 in usage (language) x4.
jufra
x1 (text) is a sentence/statement about x2 [topic/subject/predicate/focus] in language x3.
stura
x1 is a structure/arrangement/organization of x2 [set/system/complexity].