In this research, we analyze the process of expansion of the communicative repertoires during science teaching, observing how the bilinguality and literacy of the students are developed through this process. The context of the study is the English lesson integrated into the teaching of science at the Municipal School Jose Calil Ahouagi in Juiz de Fora (MG) within the project "Ensino de línguas para crianças na escola pública: abordagem CLIL" (Language teaching to children in public schools: the CLIL approach). Exploratory ethnography was the data collection and analysis methodology used. We conclude that students, in addition to learning the science content, also learned the English language, and were literate in various everyday practices, such as the understanding of the nutritional information of industrialized products, which contributed directly to the expansion of their communicative repertoires.