In CLIL (Content and Language Integrated Learning) classrooms, non-linguistic subjects are taught using a foreign language (hereafter referred to as L2). As the acronym suggests, content (C) and language (L) must be integrated into teaching, learning, and ultimately assessment. However, this paper primarily focuses on English as a Foreign Language (EFL) vocabulary instruction and the linguistic skills that subject teachers must develop to make informed pedagogical choices.

From a linguistic perspective, CLIL is a highly effective approach to increasing students' exposure to foreign languages and enhancing their language proficiency. Consequently, in addition to providing the necessary scaffolding for content comprehension and possessing adequate L2 competence, CLIL teachers must also develop a critical awareness of the most effective instructional strategies to ensure meaningful language acquisition (see Coyle & Meyer, 2021; Llinares, 2024). As noted by Coyle & Meyer (2021), language instruction within CLIL should promote deep learning, fostering long-term retention and enabling students to apply newly acquired knowledge to diverse contexts.

Coyle et al. (2010) identify three key dimensions of language in CLIL: the language of learning, the language for learning, and the language through learning. Each serves a distinct function in the CLIL classroom, guiding specific linguistic choices that subject teachers must make.

While some language skills of the CLIL classroom, particularly those categorized as the language for learning, are already developed through regular language instruction, others -especially the language of learning- must be explicitly addressed and systematically planned alongside subject content.

This paper aims to highlight key aspects of EFL instruction that subject teachers, who may have limited experience in language teaching, should consider when designing CLIL activities. In particular, it explores targeted vocabulary acquisition strategies, addressing both specialized and general vocabulary, and examining their integration with psycholinguistic language learning theories.

References:
[1] Coyle D., Hood P., & Marsh, D. (2010), CLIL- Content and Language Integrated Learning. Cambridge: Cambridge University Press.
[2] Coyle D. & O. Meyer (2021), Beyond CLIL. Pluriliteracy teaching for deeper learning. Cambridge: Cambridge University Press.
[3] Llinares, A. (2024), CLIL and Linguistics. In Banegas, D. L. & S. Zappa-Hollman (Eds.), The Routledge Handbook of Content and Language Integrated Learning. London and New York: Routledge.

Keywords: CLIL, Deep Learning, EFL instruction, Vocabulary instruction.