The article deals with the metalinguistic terminology which characterizes the grammars of the German language used in the field of German as a foreign language (Deutsch als Fremdsprache) in Italy. Starting from the basic distinction between terminological equivalence and terminological divergence, such as postulated by Kleineidam, the investigation concerns two specific fields, the terminology of, respectively, word classes and phrasal constituents, which is compared with the terminology used in teaching the native language