This paper describes the multimodal pedagogical communication of two groups of online teachers; trainee tutors (second year students of the Master of Arts in Teaching French as a Foreign Language at the University Lumie`re-Lyon 2) and experienced teachers based in different locations (France, Spain and Finland). They all taught French as a Foreign Language to a group of students from UC Berkeley in 2010. They participated in a project using a desktop videoconferencing platform (VISU1) designed for delivering online courses. The study focuses on the webcam's effects on teaching and learning and tries to answer the following question: how does multimodal interaction affect interactive learning? Our hypothesis is that experienced teachers channel information through the webcam more efficiently and effectively in order to engage learners in knowledge construction. This paper presents the results of research based on an empirical method of collecting ecological data.