This paper reports on one component of an Australian Research Council funded project which supported teachers to build a deep knowledge about language and the associated pedagogies that impacted on students’ writing outcomes. Using case study data related to primary teachers’ and students’ understandings of a functional grammar and Bernstein’s (2000) concepts of knowledge recontextualization, we explore the processes whereby student writers internalise new learning about the grammatics (Halliday, 2002) of narrative, drawing on the interpersonal resources scaffolded by their linguistically-informed teachers. We further examine the affordances and struggles manifest in their metatalk as young writers deliberately consider choices related to the interpersonal aspects of narrative writing, revealing their move from common-sense to more scientific understandings of webs of meaning.