Our paper aims to present students' interactions in a teletandem--that is, tandem through desktop videoconference [Telles, J., ed. 2009. "Teletandem. Um contexto virtual, autônomo, colaborativo para aprendizagem das linguas estrangeiras no século XXI". Campinas, SP: Pontes Editores]--telecollaborative project between third-year undergraduate students in a Chinese university and first-year graduate students in a French university. More precisely, we aim to find possible relations between the sociocultural roles co-constructed during interaction and the language learning possibilities in this teletandem environment. In our study, we adopt a socio-interactionist approach [Mondada, L., and S. Pekarek-Doehler. 2004. "Second Language Acquisition as Situated Practice: Task Accomplishment in the French Second Language Classroom." "The Modern Language Journal" 88 (4): 501-518], assuming that learning is situated in social interactions. Our corpus of analysis is formed by 15 teletandem sessions of four partnerships, which result in about 20 hours of interaction. Our analytical approach consists of three steps. First, we analyse role-taking and role-giving in terms of interlocutors' positioning as experts in relation to different topics of conversation [Reichert, T., and G. Liebscher. 2012. "Positioning the Expert: Word Searches Expertise and Learning Opportunities in Peer Interactions." "The Modern Language Journal" 96 (4): 599-609]. Second, we analyse scaffolding [Bruner, J. 1983."Le développement de l'enfant. Savoir faire, savoir dire". Paris: PUF] as it appears in different types of conversational side sequences [Jefferson, G. 1972. "Side Sequences." In "Studies in Social Interaction", edited by D. Sudnow, 294-338. New York: The Free Press] identified in studies on exolingual conversation [Porquier, R. 1984. "Communication exolingue et apprentissage des langues." In "Acquisition d'une langue étrangère III", edited by B. Py, 17-47. Paris: Presses de l'Université Paris VIII Vincennes à Saint-Denis]. Third, we observe the relations between types of role-taking and role-giving and types of scaffolding side sequences. Statistical analysis shows that some conversational phenomena are more common than others. In our opinion, the knowledge of such configurations can enrich task designers' perspectives on teletandem and possibly on telecollaboration.