Michael Halliday developed systemic functional linguistics (SFL) based on the view that language is a social semiotic system, that is a resource for making meaning. Halliday proposes that the functions that language has evolved to serve in society are reflected in its underlying organization. From this perspective, a major goal of SFL is to develop a functional grammar to account for the meaning-making potential of language:
Language has evolved to satisfy human needs; and the way it is organized is functional with respect to those needs – it is not arbitrary. A functional grammar is essentially a ‘natural grammar’, in the sense that it can be explained, ultimately, by reference to how language is used.(Halliday, 1994: viii) Similarly, systemic functional approaches to multimodal discourse analysis (SF-MDA) are concerned with the ‘grammatics’ of semiotic resources, with the aim of understanding the functions of different semiotic resources and the meanings that arise when semiotic choices combine in multimodal phenomena over space and time (O’Halloran and Lim, 2014).