noun
grammar rule
Linguistics term for a rule that governs the structure of sentences in a language.
この文法規則は例外が多い。
This grammar rule has many exceptions.
日本語の文法規則を勉強している。
I'm studying Japanese grammar rules.
文法 refers to grammar as a whole system, while 文法規則 specifically means a single grammar rule.
Compound of 文法 (grammar) and 規則 (rule).