Our research aims to explore the interpretative literary debate, a new and emblematic subject which appeared in the French primary school programs in 2002, and more particularly the conditions of its emergence as a school subject genre, from three levels: historical and epistemological, didactic, and in terms of classroom practice. To do this, we have developed the concept of the genre mega-tool, borrowed from psycholinguistics, as a place of educational intervention to build a descriptive model that can account for fields that fall within our subject, oral and literature, and translate into observable ordinary practices. We have developed this model to test two case studies in interpretation sessions of literary works. The corpus analyzed compare transcripts of sessions conducted by experienced teachers and beginning teachers, their preparation, and post-session interviews. The first case study validates the categorization of our model and specifies the linguistic components of interaction: modulation of the mediation system and report of the place of the teacher, structuring of exchange of polymanaged rounds, moving postures of student reading. The second, given over to the investment of the mega-tool by teachers to define teaching objects, plan and conduct the activity, shows that school subject genres function as an ecosystem whose components are interdependent and interrelated, and suggests the intricacy of language and subject learning.
