This is the 11944th most frequent Korean word.
노력했던
"노력했던" means "that (someone) had tried or put effort into."
The word '노력했던' is used to describe a person who had put effort in the past towards achieving something.
그는 자신의 꿈을 이루기 위해 노력했던 사람이었다.
He was a person who had worked hard to achieve his dreams.
The word '노력했던' reflects past effort collaboratively applied to the project.
우리가 함께 노력했던 프로젝트는 큰 성공을 거두었다.
The project we had worked hard on together achieved great success.
Here, '노력했던' refers to efforts made previously that led to a positive outcome.