Language use could not proceed without signals – the acts by which one person means something for another – but what exactly are they? The question is crucial because signals help define what is and what isn't language use – and language – and determine how communication is actually achieved. This chapter is addressed to what signals are and how they work.

The traditional assumption is that signals are “linguistic” objects – utterances of speech sounds, words, sentences – that work via their conventional meanings. That assumption is reflected in Austin's and Searle's terms locutionary, illocutionary, perlocutionary, and speech acts (Chapter 5). It is also reflected in the term pragmatics, the study of language use, which is treated as parallel to phonology, morphology, syntax, and semantics in the study of language. And it is reflected in the term language use, which I have felt obliged to use for this domain. More to the point, it is the working assumption of most students of language use.

That assumption, of course, isn't right. Many signals aren't “linguistic” at all (Chapters 3 and 5). The doctor waved his hand to signal Margaret that she had the measles. Sam waved a white flag to surrender. Elizabeth pointed at her mouth and an empty plate to ask for food. The sexton put one lamp in the belfry to signal Paul Revere that the Redcoats were coming by land. And as Grice (1957) noted, British bus conductors used to ring a bell twice to signal the bus driver to drive on.