On The Prepositions Which Introduce An Adjunct Of Duration

This paper deals with the prepositions which introduce an adjunct of duration, such as the English for and in. On the basis of both crosslingual and monolingual evidence these adjuncts are argued to be ambiguous between a floating and an anchored interpretation. To capture the distinction in formal terms I employ the framework of HEAD-DRIVEN PHRASE STRUCTURE GRAMMAR, enriched with a number of devices which are familiar from DISCOURSE REPRESENTATION THEORY. The resulting analysis is demonstrated to be relevant for machine translation, natural language generation and natural language understanding. 1 A typology of PP adjuncts of duration In many languages the adjuncts of duration take different forms depending on the aspectual class of the VP which they modify. In English, for instance, they are introduced by for if the VP denotes a state or a process and by in if the VP denotes an accomplishment. (1) Maria played the piano for an hour. (2) Anna wrote that letter in half an hour. Orthogonal to this distinction, there is another one, which can be made explicit by comparing (1) and (3) with (4). (3) Laura will stay in Ohio for two months. (4) Silvia has lived in Paris for three years. The adjuncts in (1) and (3) unambiguously specify the duration of Maria’s activity of playing the piano and of Laura’s stay in Ohio. The adjunct in (4), however, triggers an ambiguity: it can denote any three-year period in the past in which the state of Silvia’s living in Paris held, but it can also denote a period which started three years ago and which includes the time of utterance (Kamp and Reyle, 1993, 567). The relevance of this distinction is clear from the fact that there are languages which use different prepositions for both interpretations. Italian, for instance, employs the preposition per in the translation of (1), (3) and the first interpretation of (4), whereas it employs da in the translation of the second interpretation of (4). (5) Maria suonò il pianoforte per un’ora. (6) Laura starà per due mesi nell’Ohio. (7) Silvia ha abitato per tre anni a Parigi. (8) Silvia abita a Parigi da tre anni. For ease of reference I will call the adjuncts in (1), (3), (4a), (5), (6) and (7) floating: they denote a stretch of time whose position on the time line is not defined. The adjuncts in (4b) and (8), by contrast, will be called anchored, since their position on the time line is fixed: their right boundary is supplied by the time of utterance. As illustrated in (9-10), the right boundary can also be supplied by a temporal adjunct, such as a PP[a] or a subordinate S[quando]. (9) A at quel that punto point Silvia Silvia abitava lived da for tre three anni years a in Parigi. Paris ‘By that time Silvia had lived in Paris for three years.’ (10) Laura Laura sarà will-be nell’ in Ohio Ohio da for due two mesi, months, quando when verrà she-will-be raggiunta joined da by Ivo. Ivo ‘Laura will have been in Ohio for two months when Ivo will join her.’