The purpose of this study is to investigate the pragmatic competence of Korean EFL learners in the communicative act of complaining. This study attempt to find out whether there are differences between Native Speakers (NS) and Non-Native Speakers (NNS) in terms of their use of semantic formula when carrying out the speech act of complaining. In addition, the participants’ choice for carrying out or opting out the actual act of complaining was considered as an influential factor that plays an essential role in their pragmatic competence. Lastly, Native Korean Speakers (NKS) were also included in the study in order to determine whether there are L1 influences. 13 participants (2 NS, 7 NNS, 4 NKS) participated in Discourse Role-Play Tasks (DRPT) which included 7 situations where they had to formulate a complaint. Furthermore, they were to specify whether they would opt out or carry out the actual complaint in authentic situations. The results of the study showed that there were NS and NNS differed in terms of their use of semantic formula. For instance, NNS were shown to be overly sensitive to politeness strategies in addition to using a wide range of semantic formulae that characterize their complaints as indirect. Moreover, their choices and reasons for opting out were shown to be influential in their final oral product. Related conclusive remarks and pedagogical implications are provided.