The directive function of the English modals
The aim of this thesis is to provide a detailed account, within a 'systemic' framework of those properties of English sentences containing modal verbs, which will allow us to make predictions about the potential directiveness of some such sentences but not others, about ambiguity of communicative function, and about certain social properties of directives. Part I develops a model suitable for describing all the relevant aspects of modalised directives. We argue that no systemic model so far proposed Is, by itself, adequate for this task. We also show that the communicative function of an utterance is to be accounted for, not at the semantic level, but in terms of discourse function. Illocutionary properties are seen as relevant to the Interpretation of discourse function from the meanings of sentences uttered in contexts. A multi-level model, based on the principles of Hudson's 'daughter dependency' grammar, is proposed. Part II provides descriptions of three areas crucial to an account of modalised directives, using the framework set up in Part I. A network and realisation rules for the discourse level are proposed, and the role of directives in discourse discussed. There follows a formalised account of the semantic properties underlying mood, and the meanings of the modals. In Part III we predict, from the semantics of mood and modalisatlon, which modalised sentences will be acceptable as directives, and which of the acceptable sentences will be classified as orders, requests and suggestions, when used directively In a given social context. We also predict that, again in a given social context, certain forms of directive will be regarded as more polite than others. The results of an informant programme designed to test these hypotheses are then presented, and found to corroborate very strongly the predictions made.