What is CUP (Common Underlying Proficiency)

This chapter explores literacy development in the mother tongue (L1) in bilingual education programs. To explore the impact of Content and Language Integrated Learning (CLIL) on literacy development in L1, a large-scale study was conducted in a monolingual autonomous community (Castilla-La Mancha) located in central Spain. Scores obtained by CLIL and non-CLIL (n=4,231) learners aged 9-10 in a writing task and in a reading comprehension test were compared. Results showed CLIL was not detrimental for literacy development in L1, since no significant differences were detected between both groups in their overall proficiency in written production and reading comprehension. However, a differential achievement was observed depending on the type of instruction CLIL/non-CLIL in some areas. Significant differences were observed in favour of CLIL students in receptive vocabulary, expressive richness and spelling, whereas the non-CLIL group was ahead in critical reading, planning strategies, and use of text typologies.