42 learning. On the contrary, there are examples of failure where there is a poor teaching through another language (D. Marsh, Cambridge University Press ELT interview, 11th November, 2010). Mexico as well as other Latin American countries, has adopted CLIL mainly in bilingual private schools; only students belonging to a certain educational economic context can access this approach, depriving thousands of children who attend public institutions of this experience. The practice of CLIL usually occurs in a context in which families not only have the opportunity to pay high tuitions, but also to travel frequently to English speaking countries. The subjects that are most commonly taught in L2 are Natural Science, Arts, World History and Geography (Mextesol Convention, 2013). In middle school, high school and university, the profile required to teach content subjects makes it difficult to find teachers who fulfill the requirements stated by the authorities as they need to have a major degree as well as many years of teaching practice and at least C1 level in L2 according to CEFR (Art.34 Ley General de Educación para Profesores de Educación Secundaria). Nevertheless, professionals with a high level of English are hired to teach subjects such as Literature, Biology and even Physics and Chemistry. These teachers often need training and support to find accurate materials to include in their lessons. CAVEATS TO CLIL IMPLEMENTATION febrero 2016