“…Such investigated areas include complexity, accuracy, and fluency (CAF) in speaking (Larsen-Freeman, 2006;Lowie et al, 2017;Sauer &Ellis, 2019), andwriting (Larsen-Freeman, 2006;Spoelman & Verspoor, 2010;Verspoor et al, 2021;Zhang et al, 2022), in addition to vocabulary (Caspi & Lowie, 2013;Zheng, 2016), and pronunciation (Munro & Derwing, 2008). A number of previous studies have also examined how the dynamic development of a second language is influenced by issues such as self-concept (Mercer, 2011), motivation (Han & Hiver, 2018;Lowie & Verspoor, 2019;Nitta & Baba, 2015;Nitta & Baba, 2018;Zhang et al, 2022), individual differences (Lowie & Verspoor, 2019;Nitta & Baba, 2018;Pfenninger, 2022), and also corrective feedback (Fogal & Koyama, 2022). While these factors are indeed impactful on language developmental patterns, it does not mean that grouping learners by these variables can necessarily result in exactly similar learning patterns.…”