"CLIL refers to situations where subjects, or parts of subjects, are taught through a foreign language with dual-focussed aims, namely the learning of content, and the simultaneous learning of a foreign language".

Marsh, David. 1994. Bilingual Education & Content and Language Integrated Learning. International Association for Cross-cultural Communication, Language Teaching in the Member States of the European Union (Lingua) University of Sorbonne, Paris.

"CLIL is a generic term and refers to any educational situation in which an additional language, and therefore not the most widely used language of the environment, is used for the teaching and learning of subjects other than the language itself".

Marsh, David & Langé, Gisella. 2000. Using Languages to Learn and Learning to Use Languages. TIE-CLIL: Jyväskylä & Milan

"CLIL is an educational approach in which non-language subjects are taught through a foreign, second or other additional language".

Marsh, David et al. 2001. Integrating Competencies for Working Life. UNICOM: Jyväskylä

"The use of languages learnt in the learning of other subjects"

Lang, Jack. 2002. Foreword by Minister of Education, France in TIE_CLIL Professional Development Course. TIE-CLIL: Milan.

"Integrating language with non-language content, in a dual-focussed learning environment"

Marsh, David. 2002. CLIL/EMILE - The European Dimension: Actions, Trends and Foresight Potential. DG Education & Culture, European Commission.