Assessing language in sequential bilinguals (L2 children) for the identification of language impairment suffers from lack of appropriate standardized tools and from limited understanding of the developmental trajectories of these learners. This longitudinal study compares L2 children to children with SLI in order to better understand where these groups have overlapping performance and where they differ. An analysis of standardized test scores as well as frequency of clausal embedding and morphosyntactic errors in spontaneous speech was conducted with 22 English-speaking children (aged 6;9-12;7) acquiring French as an L2 in France and 19 monolingual French-speaking children with SLI (aged 6;5–12;11). The results revealed that L2 children used clausal embedding more often than the children with SLI, but both groups had similar rates of morphosyntactic accuracy. Facility with clausal embedding from early stages of development and continuing difficulty with morphosyntactic accuracy are argued to be characteristic of typical development in L2 children.