International audienceThis study investigates the impact of the input in language acquisition of young bilinguals (5-7 y.) from mixed French- and Russian-speaking families living in France. The results of our previous research on fluency in bilingual children’s speech productions showed the importance of the input: the French dominated in bilinguals going to French schools and children with more Russian input had a better fluency score in Russian (Tiulkova, 2017). Active and passive lexical knowledge was tested through a picture-naming task (Gagarina et al., 2015) and oral production was elicited by means of an original picture-story retelling task (similar to Mayer, 1969). Moreover, the sociolinguistic profiles of families were also taken ...