1)Can I help you? -- Yes, you can. You can help me.
2)May I come in? -- Yes, you can. You can come in.
3)Did you say that you know her? -- Yes, I did. I said that I know her.
4)Did you say you're inviting me to the theatre ? -- Yes, I did. I said that I am inviting you to the theatre.
5)Are you sure you have to leave? -- Yes, I am. I am sure that I have left.
6)Would you like a cup of tea? -- No, I wouldn't. I wouldn't like a cup of tea.
7)Can you give me a lift to the station? -- No, I can't. I can't give you a lift to the station.
8) Can you tell me the time please? -- No, I can't. I can't tell you the time.
9) Do you mind if I open a window? -- No, I don't. I don't mind if you're open a window.