Event end-state encoding in 13-month-olds—completed and non-completed events are different

Young children sometimes incorrectly interpret verbs that have a “result” meaning, such as understanding ‘fill’ to refer to adding liquid to a cup rather than filling it to a particular level. Given cross-linguistic differences in how event components are realized in language, past research has attributed such errors to non-adultlike event-language mappings. In the current study, we explore whether these errors have a non-linguistic origin. That is, when children view an event, is their encoding of the event end-state too imprecise to discriminate between events that do versus do not arrive at their intended endpoints? Using a habituation paradigm, we tested whether 13-month-old English-learning infants (N = 86) discriminated events with different degrees of completion (e.g., draw a complete triangle versus draw most of a triangle). Results indicated successful discrimination, suggesting that sensitivity to the precise event end-state is already in place in early infancy. Thus, our results rule out one possible explanation for children’s errors with change-of-state predicates—that they do not notice the difference between end-states that vary in completion.