Bilingualism is the main indicator of the current language situation in Kazakhstan. The article deals with the Russian-Kazakh bilingualism of representatives of the autokhon ethnos with the Russian language (first language) and the Kazakh language (second language). The main object of the analysis in this article is the errors that appear in the speech of bilinguals due to interference and long-term language contacts. The article describes various approaches to the study of the theory of language contacts, the phenomenon of bilingualism and interference. The paper provides an overview of the linguistic processes that have shaped the linguistic situation and linguistic policy of modern Kazakhstan, aimed at promoting the Kazakh language as the state language in the 21st century, which served as an impetus for the emergence of a new type of interference in both individual and group bilingualism. The results of a pilot paradigmatic survey are presented in the practical part of the article that demonstrates the presence of errors of an interference and conventional nature.