The manual, which is a course of lectures on the academic discipline "Ontogeny of Speech Activity", outlines the main theoretical concepts of developmental psycholinguistics (ontolinguistics), concerning the patterns of formation of speech activity and language acquisition by children as the main means of social communication, scientific theories of ontogenesis speech and the formation of language ability| a large factual material is presented that characterizes the ontogeny of speech activity in early, preschool and primary school age.In preparing the textbook, the author, one of the leading experts on the problem of the formation of coherent speech of children with speech pathology, used his own experience of scientific and research work, the subject of which is the patterns of formation of children's speech in the norm and with violations of speech development.The textbook is addressed to students of the defectological faculty, faculties of special pedagogy and psychology of humanitarian and pedagogical universities, practicing speech therapists and correctional teachers, teachers and psychologists interested in the problems of the formation of speech activity and language acquisition in ontogeny.