버린

In a sentence

• 나는 책을 잃어버린 것 같아.

  I think I lost the book.

  Here, '버린' is used as part of '잃어버린', indicating a completed action or regret of losing something.

• 그는 갑자기 일을 끝내버린 후 떠났다.

  He suddenly finished the work completely and left.

  In this sentence, '버린' in '끝내버린' emphasizes the decisiveness or finality of completing the work.

• 우리가 계획을 다 망쳐버린 것 같아.

  I think we completely ruined the plan.

  The use of '버린' in '망쳐버린' conveys a sense of irreversibility and regret in ruining the plan.