This article focuses on the meaning of nonfinite clauses ("root infinitives") in Dutch and English child language. I present experimental and naturalistic data confirming the claim that Dutch root infinitives are more often modal than English root infinitives. This cross-linguistic difference is significantly smaller than previously assumed, however. Explaining the observations, I assume that morphology operates separately from syntax and semantics (Beard (1982; 1995)) and rely on the notion of underspecification (Halle and Marantz (1993), Harley and Noyer (1999)). It is argued that the Dutch infinitival verb and the English bare verb are both underspecified vocabulary items that can be inserted in various syntactic contexts. Syntactic differences between Dutch and English result in the inclusion of tensed root infinitives in English, whereas Dutch root infinitives are limited to untensed clauses. This proposal accounts for cross-linguistic differences in the meaning of root infinitives, cross-linguistic differences in type of the verbal predicate, variability in the meaning of root infinitives, and patterns in subject selection.