This paper is based on an intervention study. It deals with research that tackles the development of professional knowledge appropriation in future teachers before they teach reading and writing (or ‘‘literacy'') in primary classrooms (ages 6–12). During the intervention, peer discussion and reflective writing tasks were organized so that students think about what it means to teach reading and writing today, in theoretical and practical terms. Each student collected many reflective texts in a personal portfolio. After the intervention, a second phase of research began. We created qualitative tools to describe and interpret how these pre-service teachers had progressively built professional knowledge about literacy teaching. First, we established five ‘‘clusters'' from indicators such as students' initial and final attitudes towards reading and writing, involvement in the training activities and progression in semiotic and reflective abilities. Then, we selected five students' portfolios (one per cluster) and proceeded to the written discourse analysis. This analysis was based on a listing of the three main categories that concerned the topics the students developed from one text to another: the reflective operations visible in the texts; and the linguistic ways of enunciation. Five different reflective pathways were identified: ‘‘comprehensive'', ‘‘prescriptive'', ‘‘pragmatic'', ‘‘heuristic-critical'' and ‘‘resistant''.