That's unclear.

　　That's clear. (那很清楚了。)

　　她到底想干什么?

　　What's she after?

　　What's she after? (她到底想干什么?)

　　I'm not sure. (我不清楚。)

　　What's her game?

　　我一點兒都不知道。

　　I have no idea.

　　Do you know where my pen is? (你知道我的筆在哪兒嗎?)

　　I have no idea. (我一點兒都不知道。)

　　I have no clue.

　　No idea.

　　It's all Greek to me.

　　我怎么不知道。

　　I didn't know that.

　　John got married last week. (約翰上星期結(jié)婚了。)

　　I didn't know that. (我怎么不知道。)

　　That's news to me. *習慣用法。

　　I wasn't aware of that.

　　不知道。/不太清楚。

　　I don't know.

　　Do you know where she's from? (你知道她是從哪兒來的嗎?)

　　I don't know. (不知道。/不太清楚。)

　　I have no idea.

　　我不太清楚。

　　I don't know for sure. *for sure 有“確切地”、“毫無疑問地”的含意。

　　Do you know the way to my house? (你認識去我家的路嗎?)

　　I don't know for sure. (我不太清楚。)

　　I don't know for certain.

　　I'm not absolutely sure.

　　誰也不知道確切的情況。

　　No one knows for sure. *這種說法與“who knows?”幾乎相同，但因為有了for sure，所以句子含有知道得不確切，但也有各種各樣的說法的語感。

　　我怎么會知道?

　　How should I know? *用于被問到“自己不可能知道”、“根本不知道”的問題時。根據(jù)說話的語氣，有時會給人以不理睬對方、冷淡對方的語感。

　　Is he married? (他結(jié)婚了嗎?)

　　How should I know? (我怎么會知道?)

　　誰能知道?

　　Who knows? *該句有時讓人聽起來有些富有哲理。

　　What is the meaning of life? (什么是人生?)

　　Who knows? (誰能知道?)

　　Nobody knows.

　　No way of knowing.

　　There's no way of knowing.

　　It's impossible to find out.