Functional theories of grammar include a range of functionally

Grammatical function

In linguistics, grammatical functions refer to functional relationships between participants in a proposition...

 based approaches to linguistics

Linguistics

Linguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....

, the scientific study of language. The grammar

Grammar

In linguistics, grammar is the set of structural rules that govern the composition of clauses, phrases, and words in any given natural language. The term refers also to the study of such rules, and this field includes morphology, syntax, and phonology, often complemented by phonetics, semantics,...

 model developed by Simon Dik

Simon C. Dik

Simon Cornelis Dik was a Dutch linguist, most famous for developing the theory of functional grammar. He occupied the chair of General Linguistics at University of Amsterdam between 1969 and 1994...

 bears this qualification in its name, functional grammar

Functional discourse grammar

Functional grammar and functional discourse grammar are grammar models and theories motivated by functional theories of grammar. These theories explain how linguistic utterances are shaped, based on the goals and knowledge of natural language users. In doing so, it contrasts with Chomskyan...

, as does Michael Halliday

Michael Halliday

Michael Alexander Kirkwood Halliday is a British linguist who developed an internationally influential model of language, the systemic functional linguistic model. His grammatical descriptions go by the name of systemic functional grammar .-Biography:Halliday was born and raised in England...

's systemic functional grammar

Systemic functional grammar

Systemic functional grammar , a component of systemic functional linguistics , is a form of grammatical description originally developed by Michael Halliday in a career spanning more than 50 years. It is part of a social semiotic approach to language called systemic-functional linguistics...

.

Role and reference grammar

Role and reference grammar

Role and Reference Grammar is a model of grammar developed by William Foley and Robert Van Valin, Jr. in the 1980s, which incorporates many of the points of view of current functional grammar theories....

, founded by Robert Van Valin is also considerered a functional theory. Another important figure in recent linguistic functionalism is Talmy Givón

Talmy Givón

Thomas Givon is a linguist and writer. He is one of the founders of functionalism in linguistics...

, but his theorising has not been given a unique name.

Dik characterises functional grammar as follows:
Because of its emphasis on usage, communicative function, and the social context of language, functional grammar differs significantly from other linguistic theories which stress purely formal approaches to grammar

Formal grammar

A formal grammar is a set of formation rules for strings in a formal language. The rules describe how to form strings from the language's alphabet that are valid according to the language's syntax...

, notably Chomskyan generative grammar

Generative grammar

In theoretical linguistics, generative grammar refers to a particular approach to the study of syntax. A generative grammar of a language attempts to give a set of rules that will correctly predict which combinations of words will form grammatical sentences...

. Functional grammar is strongly associated with the school of linguistic typology

Linguistic typology

Linguistic typology is a subfield of linguistics that studies and classifies languages according to their structural features. Its aim is to describe and explain the common properties and the structural diversity of the world's languages...

 that takes its lead from the work of Joseph Greenberg

Joseph Greenberg

Joseph Harold Greenberg was a prominent and controversial American linguist, principally known for his work in two areas, linguistic typology and the genetic classification of languages.- Early life and career :...

.