The functional neuroanatomy of language in the adult brain separates semantic and syntactic processes in the superior temporal gyrus (STG) and in the inferior frontal cortex. It is unknown whether a similar specialization is present in the developing brain. Semantic and syntactic aspects of sentence processing were investigated in 5- to 6-year-old children and in adults using functional magnetic resonance imaging. Although adults demonstrated function-specific activations in the STG and the frontal operculum, children showed a large activation overlap for these two language aspects in the STG. Compared to adults, they engaged additional areas in the left and right inferior frontal gyrus, which are known to support resource demanding processes. Thus, the language networks for semantic and syntactic processes are not yet specialized similarly to adults in the developing brain.