Intensionality and Coercion∗

Several linguistic tests were developed to distinguish aspectual classes. For example, adverbial modification with for two hours is possible with activities (John ran for two hours) but not with accomplishments (*John built a house for two years) or achievements. Temporal modification with the adverbial in two hours shows the reverse pattern. Usually only activities and accomplishments can occur in the progressive. Expressions like *knowing the answer are ungrammatical. But there is also a crucial difference in the behaviour of activities and accomplishments with respect to their progressivised forms. From John was pushing a cart we can infer that John pushed a cart. However, the inference from John was crossing the street to John crossed the ∗This paper will appear in R. Kahle (ed.), Intensionality, ASL Lecture Notes in Logic, AK Peters. This category was introduced by Moens and Steeedman, see [24].