Content-specific vocabulary in CLIL: Exploring L2 learning outcomes in a primary education programme in Catalonia

The present study seeks to explore the effects of participating in a content and language integrated learning (CLIL) programme in terms of second language (L2) content-specific vocabulary learning in a primary education school. CLIL instruction has been found to benefit the development of English L2 vocabulary, more receptive than productive. Nonetheless, little is known on content-specific vocabulary learning in CLIL and how it is supported through classroom input with young learners. We explore the impact of a 4-week CLIL programme implemented in a Catalan primary education school with a group of 16 Catalan/Spanish first language (L1) children, aged 10–11 years. Vocabulary learning was measured by means of ad hoc tests, designed on the basis of the input from the CLIL materials and targeting vocabulary depth and breadth. The results indicate that CLIL instruction positively impacted children’s depth and breadth of content-specific vocabulary knowledge. More specifically, the children experienced a significant improvement both in their receptive and productive knowledge of word meaning and form with regard to content-specific lexis. Moreover, with regard to children’s productive vocabulary knowledge as elicited through a written content task, statistical improvement was found in terms of lexical diversity and sophistication, but not lexical density. We argue for the need to use input profiled assessment instruments to appraise L2 vocabulary gains in CLIL.