Abstract
In this paper, I develop a novel interval-based approach to some well-known semantic puzzles related to aspect shift, in particular, to the interaction of for-adverbials with accomplishment and achievement verbs that take indefinite, bare plural, and mass noun complements. My approach is based on the insight that implicit frequentative aspect plays a central role in this interaction, a fact that was largely ignored in previous analyses. Specifically, I interpret frequentative aspect as an abstract verb-level pluractional operator that brings about aspect shift and that is responsible for the distribution of subevent times and subevent participants over the event time of an atelic sentence. What Zucchi and White (2001) call "the aspectual effect of frequency adverbs" thus becomes the general rule for all frequentatively understood for-adverbial sentences. Linguistic support for silent verb-level frequentativity in English is drawn from overt frequentative aspect marking in West Greenlandic verbs