생각했던

In a sentence

• 그 일이 생각했던 것보다 훨씬 더 쉬웠습니다.

  That task was much easier than I had thought.

  The word '생각했던' is used here to express the idea that the speaker had previously formed a certain expectation or thought about the difficulty of the task.

• 생각했던 계획이 변경되어 아쉽습니다.

  I’m disappointed that the plan I had thought of was changed.

  In this sentence, '생각했던' describes a plan that the speaker had previously conceived or considered.

• 그 친구는 내가 생각했던 것과는 다르게 행동했어요.

  That friend acted differently from what I had thought.

  Here, '생각했던' refers to the mental image or expectation the speaker previously had regarding their friend's behavior.