there's nothing you can do about itOften said to accept an unavoidable or disappointing situation; depending on context, it can also mean “it can't be helped.”
KO: 비가 오니까 오늘은 취소할 수밖에 없어. 어쩔 수 없지.
EN: Since it's raining, we have to cancel today. There's nothing we can do about it.