Experiments in Linguistic Meaning

This study investigates how ad-hoc implicatures and the definiteness presupposition of the definite determiner 'the' interact. Using a Truth Value Judgment Task (Crain & Thornton 2000), we examine whether English-speaking adults interpret the definite and indefinite determiner differently in sentence pairs such as: 'Mary bought a striped sweater' and 'Mary bought the striped sweater', in contexts in which there are two possible referents, one which is best described with one adjective (e.g. 'striped') and the other which is best described with two adjectives (e.g. 'striped' and 'spotted'). We find more ad hoc implicature for 'the' than 'a'; that is, uses of the definite 'the' are rejected more frequently than uses of 'a' when the purchased item would best be described with two adjectives. We take this finding to suggest that the need to satisfy the uniqueness presupposition of 'the' acts as an additional trigger for implicature generation. This result raises questions for both Neo-Gricean and localist models of implicature generation, which we briefly outline.