There’s grammar and there’s grammar just as there’s usage and there’s usage

Usage-based grammars have become increasingly prominent in recent years. In these theories usage is construed quantitatively and serves as a circumstance for the emergence and development of grammar. This paper argues that usage can go deeper than this, and may become a component of the semiotic resources of a language and a part of grammar. However, this semioticisation is restricted to interpersonal grammar, those semiotic resources of grammar that construe interpersonal meaning. Three apparently unrelated grammatical phenomena – optionality of grammatical markers, insubordination, and a range of repetition-based constructions – are shown to be unified by the notions of grammaticalised usage and interpersonal grammar. This has implications for the nature of interpersonal grammar: it represents the codification of the triadic actional frame, the basis of which is the idea that action on an interlocutor is effected via action on linguistic units.