The article deals with the problems of forming the language system of the Kazakh (native) language in
preschool age. The importance of studying the regularities and features of the formation of components of
the language system in the course of speech ontogenesis of children of early and preschool age is revealed.
It is emphasized that in the course of scientific research, as close as possible to touch the speech-motor
potential of each child, while ensuring not only a tolerant attitude to children's innovations and children's
speech style, but also to pay maximum attention to the natural process of mastering the native language and
the features of the structure of the speech-language mechanism.
The authors identified effective ways to study and explain the ontogenesis of speech – the process of
learning the native language by children. Scientific approaches to the consideration of language phenomena
in the child's speech and the prospects for conducting ontolinguistic research are also identified.