X-bar theory
IN GENERATIVE GRAMMAR, THE THEORY OF SYNTACTIC CATEGORY FORMATION THAT ① PHRASES MAY CONTAIN INTERMEDIATE CONSTITUENTS PROJECTED FROM A HEAD X; AND THAT ② THIS SYSTEM OF PROJECTED CONSTITUENCY MAY BE COMMON TO MORE THAN ONE CATEGORY (E.G. N, V, A, P)
Specifier (linguistics); X-bar syntax; Inflectional phrase; Inflection phrase; X' theory; X-bar Theory; X'; N-bar; N bar; Tense phrase; Agreement phrase; Infl; InflP; Tensed I; Maximal projection; Affix hopping; Zero-level projection; X-bar schema; Headedness principle; Headedness Principle; Binarity principle; Binarity Principle; Projection (linguistics); Intermediate projection; Affix movement; AgrP; AgreementP; Agr (linguistics); TenseP; IP hypothesis; IP Hypothesis; CP hypothesis; CP Hypothesis
In linguistics, X-bar theory is a model of phrase-structure grammar and a theory of syntactic category formation that was first proposed by Noam Chomsky in 1970Chomsky, Noam (1970). Remarks on Nominalization. In: R. Jacobs and P. Rosenbaum (eds.) Reading in English Transformational Grammar, 184–221. Waltham: Ginn. and further developed by Ray Jackendoff (1974, 1977a, 1977bJackendoff, Ray (1977b) Constraints on Phrase Structure Rules, in P. W. Culicover, T. Wasow & A. Akmajian (eds.), Formal Syntax, Academic Press, New York, pp. 249–83.), along the lines of the theory of generative grammar put forth in the 1950s by Chomsky. It attempts to capture the structure of phrasal categories with a single uniform structure called the X-bar schema, basing itself on the assumption that any phrase in natural language is an XP (X phrase) that is headed by a given syntactic category X. It played a significant role in resolving issues that phrase structure rules had, representative of which is the proliferation of grammat