In linguistics, grammar is the set of rules for how a natural language is structured, as demonstrated by its speakers or writers. Grammar rules may concern the use of clauses, phrases, and words. The term may also refer to the study of such rules, a subject that includes phonology, morphology, and syntax, together with phonetics, semantics, and pragmatics. There are, broadly speaking, two different ways to study grammar: traditional grammar and theoretical grammar.
Fluency in a particular language variety involves a speaker internalizing these rules, many or most of which are acquired by observing other speakers, as opposed to intentional study or instruction. Much of this internalization occurs during early childhood; learning a language later in life usually involves more direct instruction. The term grammar can also describe the linguistic behaviour of groups of speakers and writers rather than individuals. Differences in scale are important to this meaning: for example, English grammar could describe those rules followed by every one of the language's speakers. At smaller scales, it may refer to rules shared by smaller groups of speakers.
