Syntactic and Semantic Underspecification in the Verb Phrase.

This thesis is concerned with verbs and the relation between verbs and their complements. Syntactic evidence is presented which shows that the distinction between arguments and adjuncts reflects the optionality of adjuncts, but that adjuncts, once introduced, behave as arguments of the verb. An analysis is proposed which reflects this observation by assuming that verbal subcategorization is underspecified, so that optional constituents can be introduced into the verb phrase. The analysis is developed within a formal model of utterance interpretation. Labelled Deductive Systems for Natural Language (LDSNL), proposed in Kempson, Meyer-Viol & Gabbay (1999), which models the structural aspect of utterance interpretation as a dynamic process of tree growth during which lexical information is combined into more complex structures which provide vehicles for interpretation, propositional forms. The contribution of this thesis from the perspective of utterance interpretation is that it explores the notion of structural underspecification with respect to predicate-argument structure. After providing a formalization of underspecified verbal subcategorization, the thesis explores the consequences this analysis of verbs and verb phrases has for the process of tree growth, and how underspecified verbs are interpreted. The main argument developed is that verbs syntactically encode the possibilty for pragmatic enrichment; verbs address mental concepts only indirectly, so that the establishment of their eventual meaning, and, therefore, their eventual arity is mediated by the cognitive process of concept formation. Additional support for this view is provided by an analysis of applied verbs in Swahili which, from the perspective adopted here, can be seen to encode an explicit instruction for concept strengthening, an instruction to the hearer to derive additional inferential effects. The analysis presented in this thesis thus supports the view that natural language interpretation is a process in which structural properties and inferential activity are thoroughly intertwined.