The author begins by giving a brief explanation of the pedagogical concept of »subject-matter«. Subject-matter is of a supra-individual nature. It only comes individualized in the teaching-learning process. Subject-matter is social knowledge which the pupil acquires under the guidance of a teacher (in case of self-taught learners without a teacher). The subject-matter undergoes several transformations, each of which being connected with a different representative. If in the first phase the bearer of the subject-matter is a scientist-specialist, a scientist-educationist and the textbook writer, in the second phase the pupil and the teacher, then in the third phase the subject-matter is borne by man as a subject of practice. The second part of the article explains the actual concept of language subject- matter: it is knowledge in a foreign language which the pupil acquires under the teacher's guidance. Knowledge on the lexical level is e. g. the vocabulary given by the curriculum, on the grammatical level it consists in grammatical forms or constructions prescribed by the curriculum. The theory of language is not, strictly speaking, part of the subject-matter. Then an explanation is given of the difference between language as a practical subject and language as a theoretical subject and some remarks are made concerning the problem of the aims in regard to the subject-matter in a practical language subject. The question of the subject-matter is not an academic one, it is not a matter of futile theorizing. The clarification of this question may immediately have great practical results. It includes the questions of curricula, methodological processes, evaluation, etc.