This study examined the processing correlates of aspectual coercion among native and non-native speakers of English. For native English speakers, results suggested that the processing delay associated with aspectual coercion is minimal. Aspectual coercion was perhaps cognitively easy to perform. By contrast, non-native speakers of English from unlike first language (L1) backgrounds differed in their reading performance. The differences varied systematically as a function of aspectual contrasts in L1 after controlling for second language (L2) English proficiency. Korean participants showed trends of aspectual coercion despite the absence of significant effects; German participants exhibited indifference across experimental conditions; Chinese participants showed aspectual coercion effects opposite to the predictions specified by the English grammar. A coupling of these data with evidence from the semelfactive progressive (e.g. coughing) in English suggests that the socalled online aspectual coercion effects may arise from a prototype organization of aspectual categories that is prone to L1 influence.