In this lecture, I will describe a study at the growing edge of research on Collaborative Reasoning (CR), an approach to classroom discussion intended to be intellectually stimulating and personally engaging. The study investigated whether CR would accelerate the English language development of Spanish-speaking fifth graders from a city near Chicago. Results showed that, after participating in eight discussions over a four-week period, the CR group performed significantly better than the control group on measures of English listening, speaking, reading, and writing. The CR group produced more coherent narratives in an oral storytelling task. The reflective essays written by the CR group were longer; contained more diverse vocabulary; and contained a significantly greater number of satisfactory reasons, counterarguments, and uses of text evidence. CR discussions also enhanced students’ interest and engagement in discussions, perceived benefits from discussions, and attitudes toward learning English. I will conclude the lecture with a consideration of whether CR is likely to be effective with Chinese students learning English as a foreign language.