Normal linguistic development is dependent upon a highly organized psychic apparatus. Innate potentials for development may go awry at varying stages. In childhood autism, linguistic competence becomes fixated at early stages of language development because of underlying disturbances in mental structures. Speech-act analysis of language usefully clarifies certain aspects of autistic children's language and social difficulties. Focus on one aspect of autistic children's language—the tendency to echo when confronted by incomprehensible language demands—can illuminate the cognitive and social impairments of autistic children, one form of adaptation to their impairments, and fundamental differences in the emergence of language competence between autistic and normal children. Measures of autistic children's speech (latency of response and length of utterance) can increase our understanding of ego development by suggesting appropriate new models.