“…classroom interaction [16], strategies [17; 18], age [19], the influence of affective factors [20; 21], motivation [22], gender [22; 23], household structure [24], socioeconomic status [25; 26], became the subject of more in-depth focus. The experimental data are rather positive [27][28][29][30][31], especially concerning the positive impact of CLIL on language gains, motivation increase and positive change of attitudes towards foreign language learning; however, it is a more complex issue, and as such, the impact has to be studied and interpreted from a much broader context. Pérez Cañado studied the effects of CLIL on mother tongue (L1) and content learning, and she stresses that the CLIL students who receive instruction in L1 outperform their peers, especially in the long term, and she suggests that increased time and input are crucial for CLIL students "to achieve either the same or superior content results as their monolingual peers" [27].…”