The article considers the basic principles of grammar skills formation: selection and organization of methodical material, its systematization and classification, the problem of grammar skills acquisition over many years, and communicative methods of teaching a foreign language at the secondary stage of education. When mastering grammar in a school foreign language course, special attention should be paid to theory, using clarity, and its optimal combination with language practice. The main methodological principle is the principle of consciousness - students must be clearly aware of the communicative orientation of the studied grammatical structures and be able to decipher the schemes and tables. The communicative purpose of teaching grammar in high school allows to formulate the basic requirement for the amount of grammatical material to be mastered in high school: it must be sufficient for language use as a means of communication within the program and real for learning it in these conditions.