11. I don't know for sure.我不确切知道。
Stranger: Could you tell me how to get to the town hall?
Tom: I don't know for sure. Maybe you could ask the policeman over there.
12. I'm not going to kid you.我不是跟你开玩笑的。
Karin: You quit the job? You are kidding.
Jack: I'm not going to kid you. I'm serious.