Functional theories of grammar
Functional theories of grammar are those approaches to the study of language that see the functions of language and its elements to be the key to understanding linguistic processes and structures. Functional theories of language propose that since language is fundamentally a tool, it is reasonable to assume that its structures are best analyzed and understood with reference to the functions they carry out. Functional theories of grammar differ from formal theories of grammar, in that the latter seeks to define the different elements of language and describe the way they relate to each other as systems of formal rules or operations, whereas the former defines the functions performed by language and then relates these functions to the linguistic elements that carry them out. This means that functional theories of grammar tend to pay attention to the way language is actually used in communicative context, and not just to the formal relations between linguistic elements.
There are several distinct grammatical theories that employ a functional approach.
- The structuralist functionalism of the Prague school, was the earliest functionalist framework developed in the 1920s.
- Simon Dik's Functional discourse grammar, originally developed in the 1970s and 80s, has been influential and inspired many other functional theories. It has also been continuously developed by Linguists such as Kees Hengeveld.
- Michael Halliday's systemic functional grammar argues that the explanation of how language works "needed to be grounded in a functional analysis, since language had evolved in the process of carrying out certain critical functions as human beings interacted with their ... 'eco-social' environment". Halliday draws on the work of Bühler and Malinowski.
- Role and reference grammar, developed by Robert Van Valin employs functional analytical framework with a somewhat formal mode of description. In RRG, the description of a sentence in a particular language is formulated in terms of its semantic structure and communicative functions, as well as the grammatical procedures used to express these meanings.
- Danish functional grammar combines Saussurean/Hjelmslevian structuralism with a focus on pragmatics and discourse.
- Lexical functional grammar, developed by Joan Bresnan and Ronald Kaplan in the 1970s, is a type of phrase structure grammar, as opposed to a dependency grammar. It mainly focuses on syntax, including its relation with morphology and semantics.
Dik characterises functional grammar as follows:
In the functional paradigm a language is in the first place conceptualized as an instrument of social interaction among human beings, used with the intention of establishing communicative relationships. Within this paradigm one attempts to reveal the instrumentality of language with respect to what people do and achieve with it in social interaction. A natural language, in other words, is seen as an integrated part of the communicative competence of the natural language user. (2, p. 3)
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, notably Chomskyan generative grammar. Functional grammar is strongly associated with the school of linguistic typology that takes its lead from the work of Joseph Greenberg.
Grammatical Functions 
Functions exist on all levels of grammar, and even in phonology, where the function of the phoneme is to distinguish between lexical material.
- Semantic function: (Agent, Patient, Recipient, etc.), describing the role of participants in states of affairs or actions expressed.
- Syntactic functions: (e.g. subject and Object), defining different perspectives in the presentation of a linguistic expression
- Pragmatic functions: (Theme and Rheme, Topic and Focus) Predicate), defining the informational status of constituents, determined by the pragmatic context of the verbal interaction.
See also 
- Nichols, Johanna (1984). "Functional Theories of Grammar". Annual Review of Anthropology 13. "[Functional grammar] analyzes grammatical structure, as do formal and structural grammar; but it also analyzes the entire communicative situation: the purpose of the speech event, its participants, its discourse context. Functionalists maintain that the communicative situation motivates, constrains, explains, or otherwise determines grammatical structure, and that structural or formal approaches are not merely limited to an artificially restricted data base, but are inadequate even as structural accounts. Functional grammar, then, differs from formal and structural grammar in that it purports not to model but to explain; and the explanation is grounded in the communicative situation." Text "97-117" ignored (help)
- Dryer, Matthew S. `year=2006. "Descriptive theories, explanatory theories, and basic linguistic theory". In Felix Ameka. Catching Language: Issues in Grammar Writing. Berlin: Mouton de Gruyter. pp. 207–234. "This paper is primarily directed at linguists who can be construed as functionalist, using the term in a broad sense that includes most work in typology and work by descriptive linguists4. The central issue discussed in this paper is what sort of theory we need for linguistic description, if one adopts a functionalist view of language, which for the purposes of this paper can be characterized as the view that functional or grammar-external principles play a central role in explaining why languages are the way they are." Unknown parameter
- Newmeyer, Frederick. (2001). The Prague School and North American functionalist approaches to syntax. Journal of Linguistics vol. 37. 101 - 126
- Novak, P., Sgall, P. 1968. On the Prague functional approach. Trav. Ling. Prague 3:291-97. Tuscaloosa: Univ. Alabama Press
- Dik, S. C. 1980. Studies in Functional Grammar. London: Academic
- Dik, S. C. 1981. Functional Grammar. Dordrecht/CinnaminsonN, J: Foris.
- Hengeveld, Kees & Mackenzie, J. Lachlan (2010), Functional Discourse Grammar. In: Bernd Heine and Heiko Narrog eds, The Oxford Handbook of Linguistic Analysis. Oxford: Oxford University Press, 367-400.
- Hengeveld, Kees & Mackenzie, J. Lachlan (2008), Functional Discourse Grammar: A typologically-based theory of language structure. Oxford: Oxford University Press.
- Halliday, M.A.K. forthcoming. Meaning as Choice. In Fontaine, L, Bartlett, T, and O'Grady, G. Systemic Functional Linguistics: Exploring Choice. Cambridge University Press. p1.
- Halliday, M. A. K. 1984. A Short Introduction to Functional Grammar. London: Arnold
- Foley, W. A., Van Valin, R. D. Jr. 1984. Functional Syntax and Universal Grammar. Cambridge: Cambridge Univ. Press
- Van Valin, Robert D., Jr. (Ed.). (1993). Advances in Role and Reference Grammar. Amsterdam: Benjamins.
- Engberg-Pedersen, Elisabeth; Michael Fortescue; Peter Harder; Lars Heltoft; Lisbeth Falster Jakobsen (eds.). (1996) Content, expression and structure: studies in Danish functional grammar. John Benjamins Publishing Company.
- Bresnan, Joan (2001). Lexical Functional Syntax. Blackwell. ISBN 0-631-20973-5
- Dalrymple, Mary (2001). Lexical Functional Grammar. No. 42 in Syntax and Semantics Series. New York: Academic Press. ISBN 0-12-613534-7
- Bates, E., MacWhinney, B. 1982. Functionalist approaches to grammar. In Language Acquisition: The State of the Art, ed. E. Wanner, L. Gleitman, pp. 173- 218. Cambridge: Cambridge Univ. Press
- Dirven, R., Fried, W., eds. 1984. Functionalism in Linguistics. Amsterdam: Benjamins
- Heath, J. 1975. Some functional relationships in grammar. Language 51:89- 104
- Heath, J. 1978. Functional universals. BLS 4:86-95
- Langacker, R. W. 1974. Movement rules in functional perspective. Language 50(4):630-64
- Bybee, Joan L. (1998) A functionalist approach to grammar and its evolution. Evolution of Communication Volume: 2, Issue: 2, Pages: 249-278
- Newmeyer, Frederick. 1998. Language Form and Language Function. Cambridge, MA: MIT Press.
- Anstey, Matthew P. & Mackenzie, J. Lachlan. 2005. Crucial Readings in Functional Grammar. De Gruyter - Mouton.