Developmental aspects of language comprehension were investigated using event-related brain potentials. Children between the ages of 6 and 13 listened to passive sentences that were correct, semantically incorrect, or syntactically incorrect, and data in each condition were compared with those of adults. For semantic violations, adults demonstrated a negativity (N400), as did children, but the latency decreased with age. For syntactic violations, adults displayed an early left anterior negativity (ELAN) and a late centro-parietal positivity (P600). A syntactic negativity and a late positivity were also present for children between 7 and 13 years, again with latency decreasing with age. Six-year-olds, in contrast, did not demonstrate an ELAN effect, but a late, reduced P600 pattern for the syntactic violation condition. In the early time window, the 6-year-olds displayed a widely distributed negativity that was larger for the correct than for the syntactically incorrect condition. These data indicate that the neurophysiological basis for semantic processes during auditory sentence comprehension does not change dramatically between early childhood and adulthood. Syntactic processes for passive sentences appear to differ between early and late childhood, at least with respect to those processes reflected in the ELAN component. As there is evidence that the ELAN reflects highly automatic structure building processes, we conclude that these processes are not yet established at age 7, but gradually develop toward adult-like processing during late childhood.