The perfect tense in Korean grammar is used to describe an action that has been completed, and because of its completion, it has caused a change in the current situation or state. In Korean, the perfect tense is often expressed through the combination of the verb stem and the perfect aspect marker -으세요 (-useyo), -ㅊㅊ (-tteotteo), or -었/였 (-eot/yeot). By learning the perfect tense in Korean, you will be able to effectively communicate past events and their relation to the present.