GRAMMAR, the study of the formal features of a language [n]
The whole system and structure of a language or of languages in general, usually taken as consisting of syntax and morphology (including inflections) and sometimes also phonology and semantics
A particular analysis of the system and structure of language or of a specific language
A book on grammar
A set of actual or presumed prescriptive notions about correct use of a language
The basic elements of an area of knowledge or skill
A set of rules governing what strings are valid or allowable in a language or text