In this article, we consider the problems of preventing interlanguage interference in English language teaching in the context of trilingual education in schools in Kazakhstan. The theoretical foundations of interlanguage interference in the context of trilingual education are that:

– languages interact in a trilingual education environment;

– the objective reason for the interlanguage lexical interference and the basis for its typologization is the nature of the semantic relations between the units of the two languages, their similarity;

– interference appears in accordance with the stages of word search in different types of speech activity, when updating the semantic field, choosing a lexico–semantic group, defining a word in a synonymous group, articulation;

– interlanguage lexical interference affects the act of communication.

The prevention of interlanguage interference is expressed in the application of basic approaches, principles and methods.

The results of the experimental work confirm the effectiveness of the methodology for preventing interlanguage interference in teaching English in the context of trilingual education in schools in Kazakhstan. Based on the results of our experiment, a classification of typical errors associated with a violation of the compatibility of English words under the influence of interlanguage interference has been compiled, and the causes of these errors have been determined. The results of the study confirmed that the study of word compatibility in terms of interlanguage interference is important and relevant for the methodology of teaching foreign languages.

When writing the article, an analysis and control of the literature was carried out in accordance with the direction of the study, an analysis of state-sponsored activities in the field of a foreign language, and the pedagogical effectiveness of the study was tested in practice.