A Lexicalized Tree Adjoining Grammar for English

This document describes a sizable grammar of English written in the TAG formalism and implemented for use with the XTAG system. This report and the grammar described herein supersedes the TAG grammar described in [Abeille et al., 1990]. The English grammar described in this report is based on the TAG formalism developed [Joshi et al., 1975] which has been extended to include lexicalization ([Schabes et al., 1988]), and unification-based feature structures ([Vijay Shanker and Joshi, 1991]). The grammar discussed in this report extends the grammar presented in [Abeille et al., in at least two ways. First, this grammar has more detailed linguistic analyses, and second, the grammar presented in this paper is fully implemented. The range of syntactic phenomena that can be handled is large and includes auxiliaries (including inversion), copula, raising and small clause constructions, topicalization, relative clauses, infinitives, gerunds, passives, adjuncts, it-clefts, wh-clefts, PRO contructions, noun-noun modifications, extraposition, determiner phrases, genitives, negation, noun-verb contractions, sentential adjuncts and imperatives. The XTAG grammar has been relatively stable since November 1993, although new analyses are still being added periodically.