This study explored the reasons for the utilization of strategies in expressing gratitude among 71 college students and 29 employees of a non-sectarian private higher educational institution in the northern part of the Philippines using a mixed method of research. Descriptive-quantitative research design was used to identify the most commonly used strategy of gratitude expression by the respondents. Phenomenological study was also conducted to describe the reasons of strategies in expressing gratitude using structured interview and Discourse Completion Task (DCT) which included real-life scenarios. The gathered data were transcribed and coded through the classification of categories based on Cheng's model. The findings revealed that the respondents used varied strategies in being grateful for the favor, service or material things offered. Moreover, the respondents exhibited similarities in their reasons for using varied strategies. The key findings of the study provided implications that the proposed teaching modules were seen as relevant in enhancing the students' politeness in relation to expressing gratitude.