The Aspect Hypothesis, defective tense, and obligatory contexts: Comments on Haznedar, 2007

Haznedar (2007) argues that longitudinal data from a child learner of English who has Turkish as a first language (L1) constitute a counterexample to the Aspect Hypothesis. In this commentary, we show that her argument is not warranted because the Aspect Hypothesis does not presuppose that tense is defective, contra her claim. However, Haznedar’s finding that many achievement verbs in past tense context are left uninflected suggests that refinement of the Aspect Hypothesis may be needed.