The Aspect Hypothesis (AH) claims that L2 beginners use the perfective morpheme first with telic predicates (e.g., ‘arrive’, ‘build the house’) and only later with atelic ones (e.g., ‘know’, ‘work’). In contrast, the Lexical Underspecification Hypothesis (LUH) claims that beginners cannot represent the lexical aspect of L2 predicates (hence the telic vs. atelic distinction), because this distinction is a separate component of verb meaning. To investigate whether L2 learners distinguish between telic and atelic predicates, this study compares the responses from 299 L2 Italian learners (with different L1 backgrounds) and responses from 91 native speakers (NS) to the “for/in + time span” adverbial test (Dowty 1979). The analysis shows that native speakers and L2 learners’ responses to the adverbial test diverge significantly, with learners’ proficiency and – to a lesser extent – L1 modulating their ratings. The results suggest that native speakers and beginning-intermediate L2 learners might not represent telicity alike, either because L2 aspectual competence is still developing or because beginning learners rely on the semantic representations of their L1. These findings support the predictions of the LUH and suggest caution when trying to assess learners’ aspectual representations.