zh-CNiwms.net pic/logo.gif http://www.enun.cn Thu, 12 Jun 2008 09:52:09 GMT You must not drive fast.你不能开快车。（路险或有速度限制）
You needn’t drive fast.（时间充裕）
You must not tell others.（警告）
You needn’t tell others.（没有必要）...]]> Sat, 10 Jun 2006 00:19:58 GMT 1) 实义动词： need　（需要, 要求）
　　　　　　　 need + n. / to do sth
2) 情态动词： need，只用原形need后加do，否定形式为need not。
　　Need you go yet?
　　Yes, I must. / No, I needn't.
3) need 的被动含义：need, want, require, worth（形容词）后面接doing也可以表示被动：　
　　need doing...]]> Sat, 10 Jun 2006 00:19:58 GMT 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...]]> Sat, 10 Jun 2006 00:08:46 GMT 　would rather not do
　would rather… than…　 宁愿……而不愿。
还有would sooner, had rather, had sooner都表示"宁愿"、"宁可"的意思。
If I have a choice, I had sooner not continue my studies at this school.
　I would rather stay here than go home. = I would stay here rather than go home.
典型例题
----Shall we go skati...]]> Sat, 10 Jun 2006 00:08:46 GMT 　　had better do sth
　　had better not do sth
　　It is pretty cold. You'd better put on my coat.
　　She'd better not play with the dog.
had better have done sth表示与事实相反的结果，意为"本来最好"。
　　You had better have come earlier.
...]]> Sat, 10 Jun 2006 00:08:46 GMT 　　---Ought he to go?
　　---Yes. I think he ought to.
　　表示要求，命令时，语气由 should（应该）、had better最好）、must（必须）渐强。...]]> Sat, 10 Jun 2006 00:08:46 GMT 　　Philip may (might) have been hurt seriously in the car accident.
　　Philip can (could) have been hurt seriously in the car accident.
2)　must have +done sth，对过去时间里可能发生的事情的推测，语气较强，具有"肯定"，"谅必"的意思。
　---Linda has gone to work, but her bicycle is still here....]]> Sat, 10 Jun 2006 00:08:46 GMT 1）情态动词+动词原形。
　　表示对现在或将来的情况的推测，此时动词通常为系动词。
　　I don't know where she is, she may be in Wuhan.
2）情态动词+动词现在进行时。
　　表示对现在或将来正在进行的情况进行推测。
　　At this moment, our teacher must be correcting our exam papers.
　　这时，我们老师想必在批改试卷。
3）情态动词+动词完成时。
　　表示对过去情况的推测。
　　We would have finished t...]]> Sat, 10 Jun 2006 00:08:46 GMT 　2) must表对现在的状态或现在正发生的事情的推测时， must 后面通常接系动词be 的原形或行为动词的进行式。
　　　You have worked hard all day.You must be tired.　 你辛苦干一整天，一定累了。（对现在情况的推测判断）
　　　He must be working in his office. 他一定在办公室工作呢。
比较：
　　　 He must be staying there.　
　　　 他现在肯定呆在那里。
　　　 He must stay there.
　　　 他必须呆在那。
　3) mu...]]> Sat, 10 Jun 2006 00:08:46 GMT 　　My brother was very ill, so I had to call the doctor in the middle of the night.　我弟弟病得很厉害，我只得半夜里把医生请来。(客观上需要做这件事)
　　He said that they must work hard. 他说他们必须努力工作。（主观上要做这件事）
2)　have to有人称、数、时态的变化，而must只有一种形式。但must 可用于间接引语中表示过去的必要或义务。
He had to look after his sister yeste...]]> Sat, 10 Jun 2006 00:08:46 GMT 　　　　May God bless you!
　　　　He might be at home.
注意： might 表示推测时，不表示时态。只是可能性比may 小。
2） 成语： may/might as well，后面接不带to 的不定式，意为"不妨"。
　　　 If that is the case, we may as well try.
典型例题
　Peter ___come with us tonight, but he isn't very sure yet.
　 A. must　　B. may　 C. can　 D. will
　答案B...]]> Sat, 10 Jun 2006 00:08:46 GMT 只用于现在式和过去式(could)。be able to可以用于各种时态。
　They will be able to tell you the news soon. 他很快就能告诉你消息了。
2）只用be able to
　 a. 位于助动词后。
　 b. 情态动词后。
　 c. 表示过去某时刻动作时。
　 d. 用于句首表示条件。
　 e. 表示成功地做了某事时，只能用was/were able to， 不能用could。
　　　He was able to flee Europe before the war broke out.
　　=...]]> Sat, 10 Jun 2006 00:08:46 GMT 　2） 情态动词 除ought 和have 外，后面只能接不带to 的不定式。
　3） 情态动词没有人称，数的变化，即情态动词第三人称单数不加-s。
　4） 情态动词没有非谓语形式，即没有不定式，分词，等形式。
...]]> Mon, 24 Apr 2006 07:28:00 GMT 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. migh...]]> Mon, 24 Apr 2006 07:28:00 GMT 　 Do they have to pay their bill before the end of the month?
　 She didn't use...]]>