Introduction

As with several other terms in linguistics, the word focus means different things to different analysts. For example, it sometimes serves as a synonym for topic or topicalisation (e.g. Keesing, 1991), while at other times it indicates something quite distinct. Attempting to review all the different possible meanings or to develop an entire theory of focus, topic, and related notions is beyond the scope of this chapter, but a definition of focus is nevertheless essential. One given by Carston provides a useful point of departure: 'focus is the syntactic constituent in which dominates all the information that contributes directly to relevance' (Carston, 1996: 311).

The last word in Carston's definition is no accident, as her approach is grounded in relevance theory (e.g. Wilson & Sperber, 1993). Later in her article Carston illustrates how a particular focus construction known as an it-cleft sentence plays a special role in contributing to relevance. She contrasts a simple sentence A ROTTWEILER bit me with an it-cleft : It was a Rottweiler that bit me . According to Carston, the special syntactic structure of the latter sentence 'constrains the sort of context in which it can be appropriately used' (Carston, 1996: 312). The structure leads hearers 'to treat as a background assumption that something bit the speaker and to derive cognitive effects from the information that the entity responsible was a Rottweiler' (Carston, 1996: 312). The implied meaning (which is certainly one of the cognitive effects) could vary depending on the context, where the sentence might serve, as Carston observes, to forestall a hearer's interpretation that the dog that bit the speaker was a neighbour's Alsatian. Alternatively, the cleft might serve a speaker's aim to persuade the listener of the great danger of Rottweilers.