In this study, we compare the first and the last sessions from an online oral proficiency course aimed at doctoral students conducted in the virtual world Second Life. The study attempts to identify how supportive moves made by the teacher encourage learners to engage with language, and what type of linguistic behaviour in the learners leads to engagement in others. We compare overall differences in terms of floor space and turn-taking patterns, and also conduct a more in-depth discourse analysis of parts of the sessions focusing on supportive moves such as back-channelling and elicitors. There are indications that the supportive linguistic behaviour of teachers is important in increasing learner engagement. In our study we are also able to observe a change in student linguistic behaviour between the first and the last sessions with students becoming more active in signalling involvement as the course progresses. Finally, by illustrating some of the language awareness issues that arise in online environments, we hope to contribute to the understanding of the dynamics of online communication. (Contains 3 figures, 2 excerpts, and 9 tables.)