EN
The aim of this article is to describe how the interdisciplinary approach to teaching English, based on some aspects of content and language integrated learning (CLIL) methodology, is implemented by combining environmental science, sustainable development, and the English language. The paper introduces an English as a Second Language (ESL) course book designed for students of Environmental Monitoring, who study biomonitoring within the framework of an experimental CLIL course. At the end of each topic students present a project which proves their acquisition of professional and language knowledge. As a result, students obtain professional competence in a wide range of skills. More importantly, this goal is achieved without extending the curriculum.