Do Completely (-아/어 버리다)

-아/어 버리다 indicates that an action has been completed thoroughly or irrevocably. It adds emotional nuance — either regret for an unwanted completion, or relief that something is finally done.

Regret: 지갑을 잃어버렸어요 (I lost my wallet — unfortunately), 비밀을 말해 버렸어요 (I accidentally told the secret). Relief: 숙제를 다 끝내 버렸어요 (I finished all the homework — finally done!), 다 먹어 버렸어요 (I ate it all up).

The emotional nuance depends on context. Negative results typically convey regret, while completing difficult tasks conveys relief or satisfaction. This pattern is extremely common in everyday Korean.