The teacher-learner interaction is an indispensable factor in teaching French as a foreign language. Such interaction facilitates for the learner asking questions, expressing himself and clarifying doubts. This, in turn, helps to reach understanding. As for the teacher, he can adjust his procedures in accordance with the personal needs. This will certainly enriches the activity of the teaching process, the confidence and the motivation of the learners. This will come out with favorable circumstances of active learning. The on-line learning managed to reform the teacher-learner interaction. Technological tools provide new chances for sharing, cooperation and resilience. Yet, they sometime diminish the physical contact which may demand accommodation for the ways of interaction to keep on participation and understanding. In the mainstream of learning the understanding and writing expression in the class of French as a foreign language plays a central role. It enriches the explanation of the concepts, solving the problems, and the instant reactions. Lingual exchange process gives the learner the chance to have certain advices to improve his lingual skill, ask questions to have a better understanding. In addition, the teacher can present questions and tangible patterns to facilitate the understanding of structures and grammatical rules. This interaction strengthens the motive and encourages the active practice. It also motivates creativity in written expression.