Two episodes of tutoring through the internet have been analysed in terms of situational, interactive and content perspectives. The episodes involved secondary students who submitted queries about chemistry issues to an online service provided by teachers. Studies of the asking of questions and of the dynamics of classroom interactions are employed to discuss the interactive and content factors of this approach to teaching-learning. The functions conveyed by students' and teachers' utterances are used to identify the structural patterns of the interactions. The occurrence of classical and inverted I-R-F exchanges, the questioner's role, the continuity of the dialogues, and other structural patterns, are used to classify the episodes as being Debate and Triadic Dialogue. The notions of mastering cultural tools and scaffolding are used to account for how meaning is constructed through the interactions.