ABSTRACT
This chapter proposes an explanation for a universal tendency observed in the acquisition of tense-aspect morphology, summarized in what is known as the Aspect Hypothesis (AH; Andersen & Shirai, 1994; Bardovi-Harlig, 2000), which claims that learners create restricted form-meaning relationships at the early stages of acquiring L2 tense-aspect morphology. Specifically, learners strongly associate past tense and perfective aspect forms with punctual and telic verbs, imperfective aspect forms with atelic verbs, and progressive aspect forms with activity verbs. It is argued that learners form-meaning mapping is based on multiple factors such as input frequency, learning environment, L1 influence, and learner characteristics. The reason why so many studies converge on the predicted acquisitional pattern is that various factors work in concert, pushing learners’ form-meaning mappings in the same direction. For example, the prototype past (i.e., past tense with telic verbs) is frequent in the input, and the learners’ L1s tend to have a similar prototype.
