This article presents a pilot study carried out to investigate the potential of a functionality marker setting, included in a synchronous collaborative videoconferencing platform (VISU). Markers, supported by a trace-based system, are designed to facilitate tutors' activity. They provide tutors with (1) the possibility of annotating their distant learners' learning activity, and (2) information pertaining to their own behavior during pedagogical interaction, which can potentially enhance their professional performance as online language tutors. This study concentrates on the marker-based traces of eight language tutors collected in the course of pedagogical interactions with their distant learners during a seven-week transnational collaborative project. It presents both quantitative and qualitative analyses of the use of markers during synchronous language teaching sessions and assesses the utility and usability of such a functionality for language tutoring in order to inform future design and training.