Abstract : The aim of this thesis is to define the functioning rules of conversational systems, in order to study their process; thus, in the first part of this work, a model will be proposed to understand the creation and the evolution of conversations. in the second part of this research, the disfunctionments wich are able to emerge during situations of disagreement will be analyzed. Eventually, the third part of this subject will feature the proposed theoretical model as applied on cases of intercultural interactions. This research is based on a systemic model and has to be seen as an intercultural study of interactional and linguistic exchanges. Key points of this thesis are interindividual relations, possible cases of communicational mismatches and possible interactional power games.