why it is "실례합니다"? and "실례하다"? Duo teached us "실례하다" in weblink: https://www.duolingo.com/skill/ko/Common-Phrases-1 but i don't know what is the relation?
This may or may not help you but based off of what I learned so far,
실례합니다 is a more formal form of saying sorry. 실례하다 is not a more casual way of saying sorry and is used among friends or people close to you. The relation ship between these words has to do with the endings. The endings can change the how formal the word is. 실례합니다= 실례하다 + 입니다 (Adds more emphasis on the word, making the word 실례합니다 mean your truly sorry).
실례하다= 실례 + 하다 (하다 means to be which doesn't really add emphasis to describe how sorry you are as much as the formal way.)
Sorry if I made any mistakes. I hope this helps.