This study deals with the analysis of the speech by the teacher of mathematics in the atmosphere of the classroom. Our focus is to examine whether the teacher s speech favors or not the interaction and participation of the student in the construction of knowledge. Our starting point is the marks, which signal the stereotype created concerning Mathematics. To support our assumptions, we set our topics on the Critical Analysis of Speech, using the three-dimensional model of Fairclough. The research is of a qualitative nature, which prioritizes the interpretation of data, and starts from the analysis of some elements such as the ethos and some modalizers (verbal mode, lexical choice, intonation). For the analysis of the corpus, we used the following instruments: questionnaires, interviews and recordings of classes, duly transcribed, which gave us the support we needed to understand that the teacher and the student reflect their individual experience in the classroom and their social background interfere in the search of strategies that lead to transformation of individual and group behavior of interlocutors. Therefore we examine the construction of knowledge from the speech and the implications of the teacher s role in the classroom
