This is the 15601st most frequent Korean word.
보냈을
"Sent" (past tense of "send").
In this sentence, '보냈을' indicates the past perfect aspect, showing that sending the gift occurred before the happiness. It is part of the temporal clause '보냈을 때' meaning 'when sent'.
나는 친구에게 생일 선물을 보냈을 때 기뻤어요.
I was happy when I sent a birthday gift to a friend.
Here, '보냈을' is used in conjecture form with '겁니다,' indicating a likely action in the past regarding spending time.
우리는 여행을 계획하며 많은 시간을 보냈을 겁니다.
We probably spent a lot of time planning the trip.
In this sentence, '보냈을' is used in a hypothetical context with '지' to express curiosity or query about a potential past action.