Systemic functional linguistics

Systemic functional linguistics (SFL) is an approach to linguistics that considers language as a social semiotic system. It was developed by Michael Halliday, who took the notion of a system from his teacher, J. R. Firth. Whereas Firth thought systems referred to possibilities subordinated to structure, Halliday, in a sense, "liberated" the dimension of choice from structure and made it the central organising dimension of this theory. In other words, where many approaches to linguistic description place structure and the syntagmatic axis in the foreground, Hallidean systemic functional theory adopts the paradigmatic axis as its point of departure. The term systemic accordingly foregrounds Saussure's "paradigmatic axis" in understanding how language works. For Halliday, a central theoretical principle is then that any act of communication involves choices. Language is a system, and the choices available in any language variety are mapped using the representation tool of the "system network".

Systemic functional linguistics is also "functional" because it considers language to have evolved under the pressure of the particular functions that the language system has to serve. Functions are therefore taken to have left their mark on the structure and organisation of language at all levels, which is said to be achieved via metafunctions. The term metafunction is particular to systemic functional linguistics. The organisation of the functional framework around systems, i.e., choices, is a significant difference from other "functional" approaches, such as, for example, Dik's functional grammar (FG, or as now often termed, functional discourse grammar) and lexical functional grammar. Thus, it is important to use the full designation—systemic functional linguistics—rather than just functional grammar or functional linguistics.

For Halliday, all languages involve three generalised functions, or metafunctions: one construes experience (meanings about the outer and inner worlds); one enacts social relations (meanings concerned with interpersonal relations), and one weaves together these two functions to create text (the wording). Because these functions are considered to come into being simultaneously—viz., one cannot mean about the world without having either a real or virtual audience—language must also be able to bring these meanings together: this is the role of structural organisation, be that grammatical, semantic or contextual. These three generalised functions are termed "metafunctions".

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