<p>During teaching-learning activities, students and teachers engage in complex interactive and intersubjective processes in which both co-position each other. These processes, which, in the theory of objectification, are called processes of subjectification, are conceived as agentic processes of a cultural-historical nature. From these processes, teachers’ and students’ verbal and corporal language and emotions emerge in close relationship with how knowledge and cultural values promoted by the school are manifested. In this article, we analyze the processes of subjectification of a group of Mexican high school students during a sequence of mathematics classes in which the concept of motion is taught. The video data from the lessons were transcribed and analyzed using a semiotic multimodal dialectical methodology. Our findings provide a deeper understanding of the dialectical relationship between students’ emotions, power, and other various agentic devices that teachers and students resort to in their teaching-learning activity.</p>