While most formal semantic accounts of focus-sensitive particles such as ‘only’ acknowledge that their interpretation requires the integration of contextual information with the linguistic representation, it is less clear how this interaction plays out in real-time. Recent psycholinguistic work in this domain favors an incremental processing story, but divergent results elsewhere complicate this picture. Our findings from two Visual World eye-tracking studies (n = 33, 32) help resolve this conflict, and confirm the existence of an adult processing asymmetry: sentences in which ‘only’ associates with the subject ('Only John bought an apple') take longer to process than object-only sentences ('John only bought an apple'). We find that current accounts of the representation and exhaustification of propositional alternatives invoked by 'only' do not explain this effect. We suggest that differences at the event-structural level — which propositional alternatives arguably map onto — might explain the asymmetry.