This research studied the dynamic relationships of linguistic challenges, cultural competency, host national connectedness, and self-efficacy among expatriates. It examines how these factors affect the process of cultural accommodation in a multicultural society. The research first used a mixed-methods study, interviewing 14 expatriates to discover their personal stories and attitudes. There followed a quantitative phase. From the qualitative data, hypotheses were derived and tested empirically with a questionnaire of 211 expatriates. Statistical analysis was done with STATA software, using advanced statistical techniques such as confirmatory factor analysis and path analysis. This research finds that linguistic proficiency significantly influences cultural competency and host national connectedness. Furthermore, host national connectedness mediates the relationship of linguistic difficulties and cultural competence; self-efficacy moderates the impact of linguistic challenges on cultural competence. These results underscore the very complicated relationship between language competence, social integration, and self-efficacy in expatriates 'cultural adaptation. The current research significantly contributes original insights into the field of expatriate management and cross-cultural studies. This research highlights the manifold nature of cultural adaptation. It offers a nuanced understanding of the role of linguistic challenges, social integration, and self-efficacy play in shaping expatriates' cultural competency. The findings have significant implications for designing effective support and training programs for expatriates, enhancing their success and well-being in foreign cultural settings.