I don't know what to make of the new manager.

　　這位新經理，我不知道怎么評價他才好。

　　I don't know what you're on about.

　　我不懂你在談什么。

　　I don't know how you can say things like that.

　　真想不到你怎么會說出這種話來。

　　I don't know how she puts up with him.

　　我不明白她怎么受得了他。

　　I don't know if I can come but I'll try.

　　我不知道是否能來，但我盡可能來。