Interactions between six toddlers (aged 1;0 to 1;6) and adults were examined to ascertain adult perceptions of toddler utterance relatedness and to determine temporal and interactional features that underlie those perceptions. Five raters made judgments regarding relatedness of the child utterances to the previous adult utterances; 251 utterances were examined. Utterances judged by adults as related occurred within 4·25 seconds of the preceding adult utterance nearly 90% of the time. This study also points to the need for using interactional categories that go beyond describing utterance relatedness, and introduces terms (i.e. co-participatory, initiation, narrowed focus) for doing so.