Towards a Semantics of X-Bar Theory

Grammar encodes meaning. X-Bar Theory captures an important grammatical generalization. What is missing is a semantics of X-Bar Theory. This paper is a step towards providing such a semantics. In the process of providing a semantics for X-Bar Theory, certain modifications to X-Bar Theory are proposed to bring it into closer alignment with that semantics. Referential and relational meaning are two key dimensions of meaning that get grammatically encoded. It is argued here that the relationship between a specifier and a head is essentially referential in nature—with the specifier determining the referential status of the overall expression. It is likewise argued that the relationship between a head and its complement(s) is essentially relational, and that only relational heads (e.g. verbs, prepositions, adjectives, but not nouns) take complements. Grammar Encodes Meaning I take it as axiomatic that grammar encodes meaning. This position is consistent with Langacker’s claim (1987, p. 12) that “Grammar is simply the structuring and symbolization of semantic content.” I also take seriously Jackendoff’s Grammatical Constraint (1983, pp. 13-14) “...one should prefer a semantic theory that explains otherwise arbitrary generalizations about the syntax and the lexicon...a theory’s deviations from efficient encoding must be vigorously justified, for what appears to be an irregular relationship between syntax and semantics may turn out merely to be a bad theory of one or the other.” X-Bar Theory is an important element of a larger theory of Universal Grammar. The basic claim is that humans are born with linguistic knowledge like that captured in X-Bar Theory. Heretofore, X-Bar Theory has been investigated in largely structural terms with little consideration of its underlying semantic basis. This paper is an attempt to provide a semantic basis for X-Bar Theory and to bring syntactic theory into closer alignment with semantic theory. Two key dimensions of meaning that get grammatically encoded are referential meaning and relational meaning. As will be shown, X-Bar Theory, with some modification, can be explicated in terms of the encoding of these two dimensions of meaning. In particular, it is argued here that the relationship between a specifier and a head is essentially referential in nature—with the specifier determining the referential status of the overall expression. It is likewise argued that the relationship between a head and its complement(s) is essentially relational, and that only relational heads (e.g. verbs, prepositions, adjectives, but not nouns) take complements.