“…Early interest in spacing effects in SLA can be traced back to work by Lightbown (1998), as well as to well‐known curricular‐level investigations into the effectiveness of intensive language programs (e.g., Lightbown & Spada, 1994; see Serrano, 2012, for a review). Following Bird's (2010) study on spacing effects on L2 grammar learning, there has been a dramatic increase in the number of studies examining the effects of spacing on the learning of grammar (e.g., Kasprowicz et al., 2019; Rogers, 2015; Serfaty & Serrano, 2022; Y. Suzuki, 2017; Y. Suzuki & DeKeyser, 2017), and vocabulary (e.g., Koval, 2022; Nakata, 2015; Nakata & Elgort, 2021; Rogers & Cheung, 2020, 2021; Serrano & Huang, 2018, 2021). More recently, research has also begun to examine how spacing interacts with task repetition to influence task performance and L2 development (Bui et al., 2019; Kobayashi, 2022; Y. Suzuki, 2021; Y. Suzuki et al., 2022; Y. Suzuki & Hanzawa, 2022).…”