21.12 情態(tài)動詞的回答方式
?
   問句   肯定回答    否定回答
Need you…?  Yes, I must.   No,I needn't
Must you…?           /don't have to.

典型例題
1)---Could I borrow your dictionary?
  ---Yes, of course, you____. 
  A. might B. will  C. can  D. should
  答案表示委婉的語氣,并不為時態(tài)。答語中of course,表示肯定的語氣,允許某人做某事時,用can和 may來表達(dá),不能用could或might。復(fù)習(xí): will 與you連用,用來提出要求或下命令。should與you 連用,用來提出勸告。

2)---Shall I tell John about it?
  ---No, you ___. I've told him already.  
  A. needn't  B. wouldn't  C. mustn't  D. shouldn't
  答案A。needn't 不必,不用。 wouldn't 將不, 不會的。 mustn't 禁止、不能。 shouldn't 不應(yīng)該。本題為不需要,不必的意思,應(yīng)用needn't。

3)---Don't forget to come to my birthday party tomorrow.
  ---______.
  A. I don't  B. I won't  C. I can't D. I haven't
  答案B. will既可當(dāng)作情態(tài)動詞,表請求、建議、也可作為實義動詞表"意愿、意志、決心",本題表示決心,選B。