INTRODUCTION

Sentences are rarely uttered in a behavioural vacuum. We colour and flavour our speech with a variety of natural vocal, facial and bodily gestures, which indicate our internal state by conveying attitudes to the propositions we express or information about our emotions or feelings. Though we may be aware of them, such behaviours are often beyond our conscious control: they are involuntary or spontaneous. Almost always, however, understanding an utterance depends to some degree on their interpretation. Often, they show us more about a person's mental/physical state than the words they accompany; sometimes, they replace words rather than merely accompany them.

The approach favoured by many linguists is to abstract away from such behaviours. Generative linguists sift out extraneous, paralinguistic or non-linguistic phenomena, and focus on the rule-based grammar – the code that constitutes language. This strategy has reaped rich rewards. Over the past thirty years linguists have suggested intriguing answers to the classical questions of language study (Chomsky 1986), and are now in a position to ask questions it was once not even possible to formulate (Chomsky 2000). Linguists working within functionalist frameworks (see, for example, Bolinger 1983) have addressed non-verbal communicative behaviours, as have some conversational and discourse analysts (Goodwin 1981, Brown and Yule 1983, Schiffrin 1994) and those looking at human interaction and communication from a more sociological or anthropological perspective (Garfinkel 1967, Goffmann 1964, Gumperz 1964, 1982 Hymes 1972).