In this text, following on from our previous research project, we intend to analyse corpora of electronic plurilingual interactions (romanophone chat-rooms) involving multiple university students. These corpora refer to the Canosession of the Galanet Project (www.galanet.eu) which took place between February and March 2004. More precisely, we will observe verbal activities where, following on from seeking clarification tasks related to the co-construction of mutual comprehension, students describe and compare languages in contact. This will allow us to understand how speakers "engage themselves in a publicly intelligible and recognizable way in social activities that may be characterised as relevant within the scope of [languages] learning and acquisition" (Mondada & Doehler, 2000) [our translation]. Our conclusions will, amongst other aspects, allow us to emphasise the emergent and contingent nature of the verbal activities of co-construction of linguistic knowledge, and, simultaneously the cognitive processes that underlie them. Our work will also make it possible to analyse the role of tutors in this type of communicative situation and to have an insight into the roles they play and their needs concerning education.