Computational Lexical Semantics, Incrementality, and the So-called Punctuality of Events

The distinction between achievements and accomplishments is known to be an empirically important but subtle one. It is argued here to depend on the atomicity (rather than punctuality) of events, and to be strongly related to incrementality (i.e., to event-object mapping functions). A computational treatment of incrementality and atomicity is discussed in the paper, and a number of related empirical problems considered, notably lexical polysemy in verb argument relationships. I n t r o d u c t i o n Ever since Vendler (1957) introduced it, the socalled punctuality of achievements has been the object of many theoretical contests. After having demonstrated that punctuality actually breaks up into two, distinct notions, namely non-durativity and atomicity, I will argue here for a compositional semantic account of the latter. I will show that (non-)atomicity interacts closely with the notion of incrementality, as formulated in Dowty (1991), and that this property of verbs should be lexically encoded, although it is subject both to semantics and pragmatics-driven variations. I will finally discuss the formal specifications an NLP system could use to make predictions about atomicity and incrementality. 1. O n V e n d l e r ' s so -ca l l ed achievements Vendler (1957) defined achievements and accomplishments as respectively punctual and durative. He based his claims on two main tests, noting that at adverbials combine with achievements but not accomplishments, whereas finish combines with accomplishments but not achievements : (1 a) At what time did you reach the top ? At noon sharp. (lb) At what moment did you spot the plane ? At 10:53 A.M. (2a) *John finished leaving. (2b) John finished drawing the circle. Dowty (1986) and Moens and Steedman (1988) decisively questioned the coherence of the class of achievement verbs, arguing that not all of them are non-durative. As noted above, Vendler identifies punctual events through the conjunction of the (positive) at and (negative) finish tests. However, they do not always yield comparable results : (3a) (3b) (4a) (4b) Karpov beat Kasparov at 10.00 P.M. *The Allies beat Germany at I0.00 P.M. * Karpov finished beating Kasparov The Allies finished beating Germany. The at test fails to characterize (3b) as an achievement because it is durative, whereas (3a) passes this very test because it is non-durative. On the contrary, the fnish test in (4) yields an identical result for the beating of a chess player and that of a whole nation. It appears thus that the finish test does not indicate non-durativity, contrary to the at test, which refuses durative events, and that telic events such as (3b) fall outside Vendler's classification, since they fail both the finish test (unlike accomplishments) .AND the at test (unlike achievements). Since it