In this paper I underscore the notion of "languaging" as students' ways of functioning in and through language, particularly in interactions that involve spoken and written texts in the classroom. Thus, "to language" should be understood as active student participation - verbally, in particular - that can reveal how they deal with and respond to the challenges and opportunities that originate in the encounter with new content, or while knowledge is being constructed. I argue that "Content and Language Integrated Learning" (CLIL) is an adequate approach for school in general because it accommodates the goals of teachers of languages and teachers of other school subjects. Ultimately, mediators in both categories aim at helping their students to be able to communicate (about) what they know. In addition, I provide a few examples from research that, hopefully, can highlight the importance of opportunities to language in the classroom as a way to develop skills and confidence in formal educational contexts.