Comparatives And Ellipsis

This paper analyses the syntax and semantics of English comparatives, and some types of ellipsis. It improves on other recent analyses in the computational linguistics literature in three respects: (i) it uses no treeor logical-form rewriting devices in building meaning representations (ii) this results in a fully reversible linguistic description, equally suited for analysis or generation (iii) the analysis extends to types of elliptical comparative not elsewhere treated. INTRODUCTION Many treatments of the English comparative construction have been advanced recently in the computational linguistics literature (e.g. Rayner and Banks, 1989; Ballard, 1988). This interest reflects the importance of the construction for many natural language applications, especially those concerning access to databases, where it is natural to require information about quantitative differences and limits which are most naturally expressed in terms of comparatives and superlatives. However, all of these analyses have their defects (as no doubt does this one). The most pervasive of these defects is one of principle: they all place a high reliance on non-compositional methods (tree or formula rewriting) for assembling the logical forms of comparatives even in cases that might be thought to be straightforwardly compositional. These devices mean that the grammatical descriptions involved lack, to varying extents, the important property of reversibility: they can only be used to analyse, not to generate, expressions of comparison. This is a serious restriction on the practical usefulness of such analyses. The analysis presented here of the syntax and compositional semantics of the main instances of the English comparative and superlative is intended to provide a fairly theory-neutral ‘off the shelf’ treatment which can be translated into a range of current grammatical theories. The main theoretical claim is that by factoring out the compositional properties of the construction from the various types of ellipsis also involved, a cleaner treatment can be arrived at which does not need any machinery specific to this construction. A semantics in terms of generalised quantifiers is proposed.