With the CEFR (2001), the notion of mediation made its entry into foreign language teaching by emphasizing the fragile transition between the meanings in L1 and L2 and by proposing to treat various inter- and intralingual reformulation activities as being mediation activities. However, the specific contexts of mediation go far beyond this first suggested analytical framework. The CEFR – companion volume with new descriptors (2018) revisits, among other things, the notion of mediation and the activities that result from it. In our paper we propose to follow the “mediation of concepts,” component which seems crucial to us in the university context. It should be emphasized that for the authors of the companion volume this activity is inseparable with, on the one hand, the skills of cooperation and, on the other, the skills of carrying out group work. To move from theory to practice, we will analyze the video recordings of three different courses conducted at the Institute of French Studies in Warsaw with beginner students to draw provisional conclusions related to the subject discussed.