Twelve children (five boys and seven girls, mean age 4; I) interacted with their mothers in two conversational settings: playing with a favourite toy and helping to prepare lunch or muffins. The percentage of two topic continuation processes--topic incorporation and collaboration--used by mothers and children was analysed. It was hypothesized that the help setting with a predetermined structure would elicit a greater percentage of topic incorporation by the dyads than the play setting. In fact, the play setting elicited a greater percentage of topic incorporation from mothers than the help setting. Children did not differ significantly in the percentage of use of topic incorporation between the two settings, but appeared to be equally proficient in incorporating topics in settings with and without a predetermined structure. The play setting also elicited more topic collaboration from the children than the help setting. While the help setting appeared to support collaborative action, the play setting permitted the dyads to be informative about the toys as well as related topics. Therefore, the two settings provided different opportunities for the dyads to continue topics.