The paper explains the role of oral language and dialogic interactions in the development of individual thinking and reasoning processes. Collaborative reasoning and its contribution is explained while examples are shared to illustrate ways to scaffold students' questioning, meaning making, and writing in the context of read alouds during genre-based writing. A process to support students' written production that builds on dialogic applications of argumentative discourse is provided, too. Finally, the paper comments on ways that dialogic argumentation scaffolds students' entry into debate and written argument. Cautionary notes are provided regarding instructional practice and guidelines to teachers.