说 I don’t know 真的不礼貌吗?? | 怎么礼貌的用英语说“我...

I don't know.(這個說法沒問題，凶不凶看語氣)

I have no idea.

I haven't got a clue.

👇禮貌說法👇

I'm afraid I don't know.

Sorry,I'm not too sure/I don't know.

👇凶一點“我不知道”的說法👇

How could/should I know?

Do I look like a walking encyclopedia？