An eye movement study of temporarily ambiguous closure sentences confirmed that the early closure penalty in a sentence like "While John hunted the frightened deer escaped" is larger for a simple past verb ("hunted") than for a past progressive verb ("was hunting"). The results can be explained by the observation that simple past tense verbs convey an external viewpoint on an event, which presumably fits best when the event described has an endpoint. A definite description object supplies an endpoint. Consequently, to give up the late closure analysis of the post-verbal object when the verb is in the simple past tense, the processor is abandoning an analysis with semantically-expected properties for one which is not as good semantically. By contrast, a progressive verb denotes an activity which does not require an endpoint and therefore is neutral with respect to whether or not it takes an object.