问句 肯定回答 否定回答
Need you…？ Yes， I must. No，I needn't
Must you…？ /don't have to.
典型例题
1）——Could I borrow your dictionary？
——Yes， of course， you____.
A. might
B. will
C. can
D. should
答案C。could表示委婉的语气，并不为时态。答语中of course，表示肯定的语气，允许某人做某事时，用can和may来表达，不能用could或might复习：will 与you连用，用来提出要求或下命令。should与you 连用，用来提出劝告。
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 将不，不会的。mustn't 禁止、不能。shouldn't不应该。本题为不需要，不必的意思，应用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既可当作情态动词，表请求、建议、也可作为实义动词表“意愿、意志、决心”，本题表示决心，选B。
