The inclusion of the Knowledge about Language strand in the recently introduced Australian Curriculum: English (AC:E) is both promising and challenging. For the first time, students across primary and secondary years of schooling are expected to develop "a coherent, dynamic, and evolving body of knowledge about the English language and how it works" (ACARA 2009). Yet, it has been documented that teachers are not well equipped with their linguistic and pedagogic knowledge to translate that knowledge into productive pedagogic practices (Hammond and Macken-Horarik 2001; Jones and Chen 2012). This challenge is confounded by the debate regarding what constitutes an appropriate pedagogy for contemporary grammar teaching. Grammar teaching bears the weight of its own history of practices that were often decidedly "undialogic". Unless new ways of fostering the development of students' knowledge about language are developed, the potential of the innovative English Curriculum risks being undermined. In this study, we consider what dialogic teaching principles (Alexander 2008) might offer an engaging, productive pedagogy for grammar teaching. We offer a linguistic account of the dialogic principles as they are enacted in this classroom. Thus providing insights into the complexities of the principles in action. We also argue for knowledge of classroom talk as a resource for engaging learners with grammar and for fostering the metalinguistic understandings imagined in this curriculum reform.