This article takes stock of the current trends in research, policy and practice regarding the role of language in the dialogic classroom. The article uses the policies of two different educational jurisdictions as counterpoints to highlight the different ways that oral language can be positioned within primary curricula. It reflects on current and recent research literature, exploring how language can promote the collaborative learning that is central to dialogic pedagogy, highlighting the value of less formal registers or less 'certainty' in the proposal of ideas. The article then offers a linguistic-ethnographic analysis of what this looks like in practice, drawing on classroom observational data gathered in English primary schools. Finally, these three strands of theory, policy and practice are brought together, scoping ways forward for the inclusion of language and dialogue in primary education.