This chapter compares the acquisition of subject pronouns in French and English. I claim that the comparative child language data support a syntactic distinction between subject pronouns in the two languages. While these pronominals behave as syntactic clitics in early French, they do not in early English. The acquisition data therefore serve as a surprising source of evidence for a particular analysis of these elements in the grammar of adult spoken French. Although this chapter does not address the null subject question directly, I suggest that French is a null subject language in both its child and, seemingly, its spoken adult forms. I also hope to show how a comparison between two child grammars leads to a clearer picture of individual child grammars.