The aim of this study is to compare the semantic contingency in the father's and mother's speeches directed to the child, considering the child's participation in the conversation. Twelve (12) children between 24 and 31 months old and their respective genitors of middle-class families from the city of João Pessoa, Pernambuco, Brazil, participated in this study. The parents were videotaped when interacting with their children in a free play situation for 20 minutes in their houses. The results indicated that the mothers gave significantly more continuity to the children's speeches when compared to the fathers. In relation to other contingent behaviour, the mothers presented more recast and imitations to the boys' speech than to the girls'. These results were discussed considering the level of the children's linguist development, the context in which the interactions occurred and analyzing the implications of contingency and breakdown speech to the process of language acquisition.
ontingency; mother's speech; father's speech
