Abstract: CLIL’s main objective is giving learners a holistic educational experience where the foreign language is used not only to teach the language itself, but as a tool to explore, learn, experiment, and comprehend new concepts related to different context or areas of study (Coyle et al 2010:1). This Dissertation carries out a contrastive analysis between the materials of two subjects, Music in 1st ESO and Technology in 2nd ESO, implemented in a hard CLIL programme during the academic year 2017-2018. The aim of this piece of work is to analyse how the second language has been integrated within the content of the subjects, as both subjects have been designed in different ways: the Technology materials were created by the teacher, while the Music materials are based upon a course book. Hard CLIL programmes tend to be content led (Ball et al, 2015), so my concern is to find out whether these materials have not neglected the language learning process while teaching the specific area of study.