This paper examines the production of early verbs by two children acquiring French as their first language. The study focuses on the developmental period during which verbs are produced in one form only. Child-directed speech (CDS) and conversational contingencies (CC) occurring around these verbal forms were analyzed up to the moment when some verbs are produced in two different forms. Results show that children's use of a single form per verb can also be found in CDS by adults where the majority of verbs are used in one phono-morphological form only. Moreover, the particular form children use for a given verb corresponds to the one adults predominantly use in CDS. At the same time, child-produced verb forms are reinforced in the CC occurring in adult-child exchanges. When trying to pull apart the role of CCs from that of more general CDS, for both children we find that for about half of the verbal forms CDS and CC provide the same congruent information. Of the remaining verb types, three quarters are explained by CC, while less then 15% are explained by CDS, indicating that conversational contingencies are a stronger source of influence than general input. These findings underline the close relationships among patterns of language acquisition, conversational exchanges and child-directed speech. The data suggest a construction process based on specific characteristics of the language children hear, what they can produce and, importantly, the temporally close reinforcing relations between these two that are forged in conversational interactions.