몰랐다

In a sentence

• 어제 급한 일이 생겨서 못 갔어요, 정말 몰랐어요.

  I didn't know, as something urgent came up yesterday, and I couldn't go.

  In this sentence, '몰랐어요' is used to express a lack of awareness or knowledge about a past situation.

• 이게 그렇게 중요한 일이었는지 정말 몰랐어요.

  I truly didn't know that this was such an important matter.

  Here, '몰랐어요' conveys disregard or unawareness of the significance of something in the past.

• 사람들이 이렇게 기뻐할 줄은 정말 몰랐어요.

  I truly didn't know that people would be this happy.

  '몰랐어요' indicates being unaware of a potential outcome or reaction before it occurred.