Language of instruction

Example and reference
Appendix 2 of the Main Version of the Guide for the development of Language Education Policies in Europe. 2007. Council of Europe.
Definition
Official language (one or, in some states, more than one) or foreign language which is used as language of instruction in school. This language is not always the pupils’ “mother tongue”; the language of instruction includes forms of discourse (written discourse in particular) which are new to all learners.