않아서

In a sentence

• 비가 오지 않아서 산책을 갔다.

  Since it didn't rain, I went for a walk.

  In this sentence, '않아서' is used to indicate the reason or cause for the action that follows, meaning 'because it doesn't/didn't.'

• 나는 시간이 많지 않아서 여행을 못 갔다.

  Since I didn't have much time, I couldn't go on the trip.

  Here, '않아서' expresses a negative cause or reason related to the available time affecting the subsequent action.

• 음식이 맛있지 않아서 많이 먹지 않았다.

  Since the food was not tasty, I didn't eat much.

  In this case, '않아서' is used in a negative context related to quality, explaining why the subject did not consume much.