In recent years the interest in teaching/learning a foreign language has risen. A disappearance of borders, increased mobility and easy access to the Internet contribute to greater language awareness among learners. A new discipline of science, that is, analysis of a student’s discourse in a language classroom has also emerged. The above article focuses on a formal model of multilingualism. The work will present an analysis of students’ speaking during French lessons in the first grade in a high school. On the basis of obtained data, the author will try to establish the actual role of English during French acquisition.