Assess differences in polite expressions between second language learners and native speakers based on scenarios involving the combination of multi-factors

By methods of DCT with 24 designed continuous request-refusal dialogue scenarios and optimized classification of request and refusal strategies, differences in polite expressions between Native Korean (NK) and Chinese Korean language learners of intermediate (CKLI) and advanced (CKLA) levels were quantitatively assessed. There were significant differences in frequencies of three groups using request and refusal strategies in different scenarios. NK used more categories and numbers of strategies than CKLI. Gaps between NK and CKLI might narrow as language proficiency increases. Furthermore, not only a single influence factor affected strategy choice, but also interactions between factors, suggesting that people might behave differently when faced with complex scenarios consisting of multiple factors. The method of designing multiple independent scenarios with the same factors, and analyzing the impact of factors and their interactions on strategies used, has the potential to be applied to studies on distinctions in use of other languages or speech acts.