Collaboration between student teacher trainers, the cooperating teacher, and the university supervisor, is directly connected with the sharing of respective knowledge (Gervais & Desrosiers, 2005). However, fruitful exchanges are not necessarily usual (Sanford & Hopper, 2000), which is considered the most detrimental factor in the student teacher training process (Kauffman, 1992). This paper presents some results of a study on the circulation of knowledge between the student trainers. Data was collected using audio recordings of conversations in the natural setting of secondary teacher internship. Identification and analysis of the predominant roles illustrated in their discourse reveal that interprofessional collaboration and collaborative dialog need specific competencies.