Content and Language Integrated Learning (CLIL) is an approach where students learn a subject and a second language at the same time. In this case, it is Science (students of 3.º CEB) and Biology and Geology (secondary school students).

The content teacher teaches science or biology. Nevertheless, using CLIL as an approach is more than just switching to English to teach another subject. Content teachers are not normally experts in language acquisition or pedagogy, so they also depend on the support of the language teacher.

The language teacher is the one responsible for teaching English, but in CLIL methodology, this teacher supports the content teacher by presenting relevant vocabulary and functional language.