Vocabulary growth in young CLIL and traditional EFL learners: evidence from research and implications for education

This paper presents a three‐year longitudinal study in which the receptive vocabulary size and lexical growth of a group of CLIL learners and of traditional EFL learners are compared. CLIL approaches are considered especially beneficial in lexical development. We tested the receptive vocabulary size of 58 learners in a CLIL programme and of 49 traditional EFL learners. The 2k VLT was used. Results revealed that learners' receptive vocabulary sizes lie within the most frequent 1,000 words, although CLIL learners throw significantly higher vocabulary scores in the last grades tested. Incorporation of new words each grade remains stable for both cohorts, although the vocabulary size of CLIL learners increases with grade. We believe that the CLIL approach offers a benefit for vocabulary acquisition, which grows as experience with the approach, age and proficiency augment.