“…CLIL refers to a curriculum-based approach in which content courses are taught using a second language, to teach both content and language through immersion. Although research on the language learning aspects of CLIL quite conclusively shows an improvement in FL use and comprehension (Admiraal, Westhoff, & De Bot, 2006; Aguilar & Rodríguez, 2012; Bergroth, 2006; Dalton-Puffer, 2007; Jiménez Catalán & Ruiz de Zarobe, 2009; Ouazizi, 2016; Serra, 2007; Xanthou, 2011; although see Dallinger, Jonkmann, Hollm, & Fiege, 2016 for no improvement), the research on content learning is less clear-cut (Dalton-Puffer, 2011). There are studies that find positive effects (Day & Shapson, 1996; Jäppinen, 2005; Ouazizi, 2016; Pérez Cañado, 2018; Surmont, Struys, Van Den Noort, & Van De Craen, 2016; Van de Craen, Ceuleers, & Mondt, 2007; Xanthou, 2011), while others find negative (Anghel, Cabrales, & Carro, 2016; Dallinger et al, 2016; Fernández-Sanjurjo, Fernández-Costales, & Arias Blanco, 2017) or null effects (Admiraal et al, 2006; Bergroth, 2006; Serra, 2007; Stohler, 2006).…”