“…The study, adopting a pretest-posttest design, recruited 9 participants who and I-I) as measured by pretests and posttests, which could be attributed to the fact that the former two pairs engaged in a larger amount of and more types of languaging than the latter two pairs/groups. To summarize, all four studies observed the positive learning effect of languaging on grammar understanding and use, and they respectively revealed the impact of learners' existing grammar knowledge (Swain et al, 2009), quantity and quality of languaging , and proficiency pairing/grouping (Li, 2015), as well as the process of cultivating scientific concept about grammar ). Yet, the studies cannot inform us about whether languaging is more effective and efficient than other methods, say, teacher-fronted instruction in facilitating grammar learning since they did not incorporate any control or comparison group.…”