This article is concerned with how developing writers use grammar knowledge to make choices in writing and the extent to which this knowledge is conscious and the choices deliberate. Drawing on case study data with 24 school-aged writers involved in a three-year longitudinal study, the article reports the pattern of conscious and unconscious choices being made. It will reveal how curriculum emphasis has tended to prioritise grammatical use over rhetorical purpose, thus raising grammatical use to conscious awareness. The data also shows how linguistic understanding appears first in text before being articulated as a conscious choice; thus raising a question as to the value of conscious and explicit grammatical understanding. The article will argue for a pedagogy that creates a space to talk about choices in order to lift unconscious writing decisions into conscious and useable awareness.