This paper investigates the interaction of prosodic information and discourse principles in child language, taking sentences with the focus operator only as a case study. For adults, prosodic information alone can influence the truthconditional interpretation of (otherwise) ambiguous sentences. However, the findings of two experiments demonstrate that children are not able to use prosodic information alone to resolve certain ambiguities involving the focus operator only. The next section reviews the semantic properties of the focus operator only. Then we review the relevant prior literature on child language, before turning to our own experimental studies.