This article analyze the discourse and practice of teachers in the didactics interaction associated with cognitive types at classroom. It́s used qualitative analysis of interviews - Content Analysis of discourse-, and quantitative analysis of teacher-students dialogic structures, from 32 classes of 8 teachers with practices to promote learning. The results indicate effective teachers in vulnerable social contexts:1) Repeatedly explains the class content; 2) The content is orders in a gradual process of complexity, 3) They have two goals in the classroom: making learning, and train students in civic values, and 4) The percentage of dialogic structures of low cognitive demand, are majority in these teachers. These results are discussed.