This is the 998th most frequent Korean word.
모르겠다
"I don't know."
The word '모르겠어요' is used to express uncertainty or lack of knowledge about the reason.
저는 여기에 왜 왔는지 모르겠어요.
I do not know why I came here.
'모르겠어요' here signifies uncertainty about a future event.
그는 언제 올지 모르겠어요.
I do not know when he will come.
'모르겠어요' expresses lack of comprehension due to difficulty.