This study aimed to investigate the effect of L2 grit on the communication strategies employed by Chinese Japanese-as-a-foreign-language (JFL) learners. Additionally, it explored how this effect varies depending on learners’ cognitive flexibility and language proficiency. The findings revealed the following: (1) There were no significant variations in the use of communication strategies among learners based on their proficiency levels. (2) L2 grit had a significant impact on the learners’ use of communication strategies. (3) As proficiency levels increased, a transition from a complementary relationship between cognitive flexibility and L2 grit to a synergistic relationship was observed.
