This paper uses Conversation Analysis to investigate the organisation of topic talk during interactions involving a person with aphasia (Valerie). Approximately three and a half hours of everyday conversation between Valerie and her conversation partners was collected and analysed. It was found that Valerie’s conversation partners took on primary speakership more often during topic talk, and held the floor for longer periods of time. It is argued that this pattern was the product of weak alignment with Valerie’s topic talk initiations, trouble that arose during Valerie’s extended turns, and Valerie’s promotion of speakership for her conversation partners. These observations point towards the importance of conversation partners’ conduct in promoting the success of extended turns produced by people with aphasia. Finally, it is suggested that the findings of interaction-focused research can help specify and expand notions of functional communication.