Importance. Traditional methods and approaches in learning English language are substituted by digitalization of the educational process. The research aimed at developing and testing the methodology of teaching a foreign language to students of a technical university through educational interaction with a chatbot with generative AI, the purpose of which is to identify the effectiveness of the use of digital tools in pedagogical practice is determined as relevant and demanded.Research Methods. The research material was theoretical, empirical and analytical methods. First-year students of National Research Nuclear University “MEPhI” participated in the experiment on differentiated teaching of English grammar to students of technical universities by means of educational interaction with an AI chatbot.Result and Discussion. The experiment consisted of three stages: ascertaining, formative and control. At the first stage, an entrance grammar test was conducted to determine the initial level of grammatical skills of students in the control and experimental groups. At the second stage, the experimental group was taught English grammar using the proposed methodology, while the students of the control group were taught in the traditional way. At the last stage, the students of the two groups underwent final grammar testing, which allowed us to compare the results and conduct statistical analysis of the data.Conclusion. The statistical data confirm the validity of the author's methodology for differentiated teaching of English grammar to students of technical university through educational interaction with a chatbot.