Korean has variety endings as one of the characteristic features. Korean express themselves deeply and delicately with these endings. However learners of Korean as a Second language or Korean as a Foreign Language have difficulties in learning and acquiring Korean endings because of their diversity and subtle differences. ‘-eulge’ and ‘-eulrae’ is one of the difficult endings to differentiate for learners. Native Koreans distinguish and use each of them naturally and automatically. But it is a not easy to explain the differences of usages between ‘-eulge’ and ‘-eulrae’ even for native Koreans. Both of them express ‘future’ and ‘intention’. But ‘-eulrae’ is used with positive answer to ‘order’, ‘asking’, ‘suggestion’ or ‘request’. On the contrary ‘-eulge’ is used with negative answer to them. Though we could observe diverse usages of ‘-eulge’ and ‘-eulrae’ like ‘-eulge’ using for ‘making promise’ expression or ‘-eulrae’ using for expression of asking listeners intention. We could summarize their difference as ‘acceptance’ and ‘denial’. This study explains how we could classify the usage of ‘-eulge’ as acceptance of listener’s intention and the usage of ‘-eulrae’ as refusal of listener’s intention. This classification could help KSL, KFL leaners to learn them as well as teachers to teach them. (HankukUniversity of ForeignStudies)