Lexical-functional grammar


Lexical functional grammar (LFG) is a constraint-based grammar framework in
theoretical linguistics Theoretical linguistics is a term in linguistics which, like the related term general linguistics, can be understood in different ways. Both can be taken as a reference to theory of language, or the branch of linguistics which inquires into the Phi ...
. It posits two separate levels of syntactic structure, a
phrase structure grammar The term phrase structure grammar was originally introduced by Noam Chomsky Avram Noam Chomsky (born December 7, 1928) is an American linguist Linguistics is the scientific study of language A language is a structured system ...
representation of word order and constituency, and a representation of grammatical functions such as subject and object, similar to
dependency grammar Dependency grammar (DG) is a class of modern grammatical In linguistics Linguistics is the science, scientific study of language. It encompasses the analysis of every aspect of language, as well as the methods for studying and modeling th ...
. The development of the theory was initiated by
Joan Bresnan Joan Wanda Bresnan Fellow of the British Academy, FBA (born August 22, 1945) is Sadie Dernham Patek Professor in Humanities Emerita at Stanford University. She is best known as one of the architects (with Ronald Kaplan) of the theoretical framework ...
Ronald KaplanRonald M. Kaplan (born 1946) has served as a Vice President at Amazon.com and Chief Scientist for Amazon Search ( A9.com). He was previously Vice President and Distinguished Scientist at Nuance Communications Nuance is an American Multinationa ...
in the 1970s, in reaction to the theory of
transformational grammarIn linguistics Linguistics is the science, scientific study of language. It encompasses the analysis of every aspect of language, as well as the methods for studying and modeling them. The traditional areas of linguistic analysis include pho ...

transformational grammar
which was current in the late 1970s. It mainly focuses on
syntax In linguistics, syntax () is the set of rules, principles, and processes that govern the structure of Sentence (linguistics), sentences (sentence structure) in a given Natural language, language, usually including word order. The term ''syntax'' ...

, including its relation with
morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines * Morphology (archaeology), study of the shapes or forms of artifacts * Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies ...
semantics Semantics (from grc, σημαντικός ''sēmantikós'', "significant") is the study of reference Reference is a relationship between objects in which one object designates, or acts as a means by which to connect to or link to, another o ...
. There has been little LFG work on
phonology Phonology is a branch of that studies how languages or dialects systematically organize their sounds (or constituent parts of signs, in sign languages). The term also refers to the sound or sign system of any particular language variety. At on ...

(although ideas from
optimality theory In linguistics, Optimality Theory (frequently abbreviated OT) is a linguistic model proposing that the observed forms of language arise from the optimal satisfaction of conflicting constraints. OT differs from other approaches to phonological a ...
have recently been popular in LFG research).


LFG views language as being made up of multiple dimensions of structure. Each of these dimensions is represented as a distinct structure with its own rules, concepts, and form. The primary structures that have figured in LFG research are: * the representation of grammatical functions (f-structure). See
feature structureIn phrase structure grammars, such as generalised phrase structure grammar, head-driven phrase structure grammar and lexical functional grammar, a feature structure is essentially a set of attribute–value pairs. For example, the attribute named ''n ...
. * the structure of syntactic constituents (c-structure). See phrase structure rules, ID/LP grammar. For example, in the sentence ''The old woman eats the falafel'', the c-structure analysis is that this is a sentence which is made up of two pieces, a noun phrase (NP) and a verb phrase (VP). The VP is itself made up of two pieces, a verb (V) and another NP. The NPs are also analyzed into their parts. Finally, the bottom of the structure is composed of the words out of which the sentence is constructed. The f-structure analysis, on the other hand, treats the sentence as being composed of attributes, which include feature (linguistics), features such as number and Grammatical tense, tense or functional units such as subject (grammar), subject, predicate (grammar), predicate, or Object (grammar), object. There are other structures which are hypothesized in LFG work: * argument structure (a-structure), a level which represents the number of arguments for a predicate and some aspects of the lexical semantics of these arguments. See theta-role. * semantic structure (s-structure), a level which represents the meaning of phrases and sentences. See Glue Semantics. * information structure (i-structure) * morphological structure (m-structure) * phonological structure (p-structure) The various structures can be said to be mutually constraining. The LFG conception of linguistic structure differs from Noam Chomsky, Chomskyan theories, which have always involved separate levels of constituent structure representation mapped onto each other sequentially, via transformations. The LFG approach has had particular success with Non-configurational language, nonconfigurational languages, languages in which the relation between structure and function is less direct than it is in languages like English; for this reason LFG's adherents consider it a more plausible universal model of language. Another feature of LFG is that grammatical-function changing operations like Grammatical voice, passivization are relations between word forms rather than sentences. This means that the active-passive relation, for example, is a relation between two types of verb rather than two trees. Active and passive verbs involve alternative mapping of the participants to grammatical functions. Through the positing of productive processes in the lexicon and the separation of structure and function, LFG is able to account for syntactic patterns without the use of transformations defined over syntactic structure. For example, in a sentence like ''What did you see?'', where ''what'' is understood as the object of ''see'', transformational grammar puts ''what'' after ''see'' (the usual position for objects) in "deep structure", and then moves it. LFG analyzes ''what'' as having two functions: question-focus and object. It occupies the position associated in English with the question-focus function, and the constraints of the language allow it to take on the object function as well. A central goal in LFG research is to create a model of grammar with a depth which appeals to linguists while at the same time being efficiently parsable and having the rigidity of formalism which computational linguists require. Because of this, computational parsers have been developed and LFG has also been used as the theoretical basis of various machine translation tools, such as Apptek, AppTek's TranSphere, and the Julietta Research Group's Lekta.

See also

*Glue semantics, a theory of the syntax-semantics interface *Head-driven phrase structure grammar *Relational grammar *Tree-adjoining grammar


*Bresnan, Joan (2001). ''Lexical-Functional Syntax''. Blackwell. *Bresnan, Joan; Asudeh, Ash; Toivonen, Ida; Wechsler, Stephen (2015). ''Lexical Functional Syntax.'' 2nd edition. Wiley Blackwell. *Dalrymple, Mary (2001). ''Lexical Functional Grammar''. No. 42 in ''Syntax and Semantics'' Series. New York: Academic Press. *Dalrymple, Mary; Lowe, John J.; Mycock, Louise (2019). ''The Oxford Reference Guide to Lexical Functional Grammar''. Oxford: Oxford University Press. *Falk, Yehuda N. (2001). ''Lexical-Functional Grammar: An Introduction to Parallel Constraint-Based Syntax''. CSLI. *Kroeger, Paul R. (2004). ''Analyzing Syntax: A Lexical-Functional Approach''. Cambridge: Cambridge University Press.

External links

Lexical Functional Grammar Home PageProceedings of the annual LFG conferenceLexical Functional Grammar course lectures on YouTube, Prof Miriam Butt, University of Konstanz
{{Authority control Generative linguistics Grammar frameworks Syntactic theories