Language Acquisition in CLIL and Non-CLIL Settings builds a bridge between Second Language Acquisition and Learner Corpus Research (LCR) methodologies to take the evaluation of Content and Language Integrated Learning (CLIL) to a new level. The study innovates in two main ways. First, it is based on a highly diversified L2 database which includes learner corpus data as well as experimental data from the same learners. These linguistic components of the database are complemented with extensive information on learner variables, including cognitive and affective factors, which are rarely studied in LCR. Second, the study relies on multifactorial statistical analyses to assess the effectiveness of CLIL itself as well as the impact of the selectivity inherent in the CLIL system, which has frequently been ignored. The linguistic focus of the study is the English passive, which is investigated in CLIL and non-CLIL teaching materials, and subsequently related to learner output.