In this paper we suggest a practical, talk-based model for the successful pursuit of teaching science in primary classrooms (Loxley et al., 2010). This model is not only based on our own experience of teaching in primary schools, and of training teachers to do so, but is also based substantially on research on classroom talk, which has built upon the foundations established by Douglas Barnes. We begin by setting out the three-stage model and then go on to illustrate how it can be put into practice.