This chapter focuses on how teachers support productive class dialogues in the new situations that digital technologies create. It reviews the literature on digital technology and classroom dialogues and analyse the empirical cases using microblogging. The chapter draws on data from a research project in which teachers were encouraged to use a microblogging tool called Talkwall in combination with material from the ‘thinking together’ approach. It examines the role that ground rules for classroom interaction play and the work needed in technology-rich classrooms to facilitate productive classroom dialogues. The chapter introduces the research literature on how to establish and sustain an efficient classroom environment and how ground rules can support this work, especially with the rapidly increasing use of digital technologies. It also focuses on how digital technology, and microblogging in particular, can facilitate classroom dialogue. The chapter also draws on video data from classroom situations, audio recordings of interviews, classroom observations and logs from Talkwall.