Recent studies have highlighted the benefits of CLIL instruction regarding general competence in the acquisition of second languages. However, it is not clear whether these benefits extend to specific areas of grammar. Here we compare the general proficiency and specific linguistic features of a group of learners of L3 English in a CLIL programme with two EFL groups: one matching the CLIL group in age and hours of exposure and a second group two grades ahead. The results confirm that the benefits of CLIL in general competence do not extend to the acquisition of specific linguistic features. In this respect, the best results were obtained by the older EFL learners suggesting that CLIL benefits do not extend to the acquisition of English verbal morphology.