Classroom dialogue has been the focus of educationists' attention for over 60 years (Myhill 2018), most recently manifest in the work of Alexander (2017); Edwards-Groves & Davidson (2017); Resnick, Michaels & O'Connor (2010) and Mercer, Dawes & Kleine Staarman (2009). In concert with this work, systemic functional linguists have developed useful tools for describing the character and quality of talk in classrooms (e.g. Christie, 2002; Hammond & Gibbons, 2005). However, despite such activity, the interaction patterns through which learners become constituted as more or less successful remain largely invisible to many teachers and students. This paper builds on recent work exploring the intersection of systemic functional linguistics (SFL) and dialogic pedagogy (Jones & Hammond, 2019). Here, we report on collaborative research from three different Australian classrooms in which teachers worked to enhance the quality of talk (Jones, Simpson & Thwaite, 2018). We draw on SFL (Halliday & Matthiessen, 1999), in particular, the systems of Speech Function (Eggins & Slade, 1997) and Exchange Structure (Martin & Rose, 2007), to illuminate how different pedagogic practices are enacted in the unfolding interactions between teachers and students. We argue that a functional linguistic approach makes visible, in a theoretically principled way, how micro-level adjustments to talk patterns can lead to more productive, dialogic classrooms.