“…Like these ML learners, immersion learners typically begin young, and have many hours a week of communicative L2 exposure from native speakers (or highly proficient speakers) of the L2. However, like instructed-L2 learners, the exposure that immersion learners receive is largely limited to the classroom in communities where the L2 is a foreign (or minority) language, making them similar to the participants of studies of instructed-L2 classrooms (e.g., Butler & Le, 2018;Muñoz, Cadierno, & Casas, 2018;Sun, Steinkrauss, Tendeiro, & de Bot, 2016). Though immersion contexts are not likely to reach the same quantity of L2 exposure as ML contexts, learners in these programs can amass around 6,000 hr of L2 exposure by their middle-school years (Turnbull, Lapkin, Hart, & Swain, 1998), which far exceeds that of instructed-L2 contexts, for which L2 exposure is limited to only a few hours a week and where total classroom exposure may only be around 800 hr by the end of compulsory education, though this will vary widely by program (Muñoz, 2008).…”