Systemic functional grammar (SFG) or systemic functional linguistics (SFL) is a model of grammar that was developed by Michael Halliday in the 1960s. It is part of a broad social semiotic approach to language called systemic linguistics. The term "systemic" refers to the view of language as "a network of systems, or interrelated sets of options for making meaning"; The term "functional" indicates that the approach is concerned with meaning, as opposed to formal grammar, which focuses on word classes such as nouns and verbs, typically without reference beyond the individual clause.
Systemic functional grammar is concerned primarily with the choices that the grammar makes available to speakers and writers. These choices relate speakers' and writers' intentions to the concrete forms of a language. Traditionally the "choices" are viewed in terms of either the content or the structure of the language used. In SFG, language is analyzed in three different ways, or strata: semantics, phonology, and lexicogrammar. SFG presents a view of language in terms of both structure (grammar) and words (lexis). The term "lexicogrammar" describes this combined approach.
Within the semantic domain, SFG proponents examine the subject matter of a text through organizing its nouns, lexical verbs, adjectives, and adverbs. These are the words which carry meaning in a text, as opposed to function words, whose purpose is grammatical.
Examining the angle of representation involves a close look at types of processes, participants, and circumstances.
The speaker/writer persona concerns the stance, personalization and standing of the speaker or writer. This involves looking at whether the writer or speaker has a neutral attitude, which can be seen through use of positive or negative language. Social distance means how close the speakers are, e.g. how use of nicknames shows the degree to which they are intimate. Relative social status asks whether they are equal in terms of power and knowledge on a subject, for example, the relationship between a mother and child would be considered unequal. Focuses here are on speech acts (e.g. whether one person tends to ask questions and the other speaker tends to answer), who chooses the topic, turn management, and how capable both speakers are of forming evaluations on the subject.
Textual interactivity is examined with reference to disfluencies such as hesitators, pauses and repetitions.
Spontaneity is determined through focus on lexical density, grammatical complexity, coordination (how clauses are linked together) and the use of noun phrases. The study of communicative distance involves looking at a text’s cohesion, that is, how it hangs together, as well as any abstract language it uses.
Cohesion is analysed in the context of both lexical and grammatical as well as intonational aspects with reference to lexical chains and, in the speech register, tonality, tonicity, and tone. The lexical aspect focuses on sense relations and lexical repetitions, while the grammatical aspect looks at repetition of meaning shown through reference, substitution and ellipsis, as well as the role of linking adverbials.
Systemic functional grammar deals with all of these areas of meaning equally within the grammatical system itself.
Another way to understand the difference in concerns between functional and generative grammars is through Chomsky's claim that "linguistics is a sub-branch of psychology." Halliday investigates linguistics as though it were a sub-branch of sociology. SFG therefore pays much more attention to pragmatics and discourse semantics, at the expense of an easily computable formalism.
Other significant systemic functional grammarians:
Linguists also involved with the early development of the approach: