This article discusses the constructivism as a base theory for the learning of german as a foreign language. The constructivism expresses the theory that knowledge is built by the learner, not supplied by the teacher. Knowlidge is not passively received, but is actively built up by the cognizing subject. That is, as much as we as teachers would like to, we cannot put ideas into student‘s heads, they will and must construct their own meanings. The constructionism expresses the further idea that this happens especially felicitously when the learner is engaged in the construction of something external or at least shareable. This leads to a model using a cycle of internalization of what is outside, then externalization of what is inside and so on. The function of cognition is adaptive and serves the organization of the experimental world.