2015专四语法考点：情态动词

　　英语语法是组词造句的规则，是把合适的词放进合适位置的艺术，语法可分为两大部分：词法和句法。新东方在线将为专四考生们详细解析专四语法考点。

2015专四语法考点：情态动词

*情态动词: will（愿意）, shall（将）, must（必须）, can, may, would, should (应该), might, could, ought to, used to（过去常常）, need（需要）, dare（竟敢），have to（不得不）

考试中，情态动词部分重点测试以下内容：
（1）情态动词+行为动词完成式（表示推测）
（2）某些情态动词的特殊用法　

考点1. 情态动词＋have＋过去分词结构表示推测

(1) must have v-ed表示推测过去某事“一定”发生了。否定形式为：can’t / couldn’t have v-ed, 表示过去不可能发生某事。

1. Nancy's gone to work but her car's still there. She _must have gone ___ by bus.2010

A. must have gone B. should have gone C. ought to have gone D. could have gone

2. She _must have been ____ fifty or so when I first met her at the conference.2009/2007

A. must be B. had been C. could be D. must have been

3. Which of the following sentences expresses "probability"可能性超级大啊?2008

A. You must leave immediately. B. You must be feeling rather tired.

C. You must be here by eight o'clock. D. You must complete the reading assignment on time.

4. He _could not have caught____ the 8:20 bus because he didn’t leave home till 8:25. (1994)

A. can not /couldn’t have caught B. ought to have caught C. shouldn’t have caught D. must not have caught

5. –“She must be in the dormitory now.”

--“No, she _can n ot ___ be there. I saw her in the classroom a minute ago.”(1994)

A. mustn’t B. can’t C. couldn’t D. wouldn’t

6. –“The door was open.”

--“It _cannot have been___ open. I had locked in myself and the key was in my pocket.”(1992)

A. can’t be B. mustn’t be C. can’t have been D. mustn’t have been

(2) could have v-ed 表示推测过去某动作“很可能”发生了。

(3) may / might have v-ed 表示推测过去某事“也许”发生了.

1. He __may have acted __ unwisely, but he was at least trying to do something helpful. (1999)

A. may have acted B. must have acted C. should act D. would act

(4) ought to / should have v-ed 和 ought not to / shouldn’t have v-ed 用于对已发生的情况表示“责备”、“不满”，分别表示“本应该…”和“本不应该…”表示应完成而未完成的动作用于完成时中的否定句，表示不应完成但已做的动作

1. Aren't you tired? I _should have thought___ you had done enough for today.2009
A. should have thought B. must have thought C. might have thought D. could have thought

(5) needn’t have v-ed 表示过去做了某事，但没有做的必要，意为“本没必要…”。注意：did not need to do 动作并没发生。例：I didn’t need to get up early,so I got up until 9 a.m.

1. You _neednot have told___ Jim anything about it. It was none of his business. (2000/1998)

A. needn’t have told B. needn’t tell C. mustn’t have told D. mustn’t tell

2. As it turned out to be a small house party, we _need not have dressed up____ so formally. (1996)

A. need not have dressed up B. must not have dressed up C. did not need to dress up D. must not dress up

3. The meeting’s been cancelled. Ann _need not have done___ all that work. (1995)

A. need to do B. need have C. needn’t have done D. needed not to do

考点2. 特殊用法　

(1) can't“不可能”（表推测）, may not “可能不”（表推测）, mustn’t (must not) “不要; 禁止”; used not／usedn’t to或didn’t use to… 过去不…

(2) should 表示惊讶

1. I am surprised_that you should think_ this city is a dull place to live in.2006

A. that you should think B. by what you are thinking

C. that you would think D. with what you were thinking

(3) 用于过去式中，can常表示能过做某事，但事实不一定去做；be able to则表示能做某事并且已经做了。

1. I went there in 1984, and that was the only occasion when I _was able to make_______ the journey in exactly two days.2005

A. must take B. must have made C. was able to make D. could make

(4) Can’t but + V.,表示不得不，与have to同义。Can’t help +Ving, can’t help but +V.表示忍不住。

(5) may/ might as well + 动词原形”意为“最好，满可以，倒不如”，相当于had better

(6) may well + 动词原形”是一种常见的结构，意为“（完全）能，很可能” : He may well be proud of his son. 他大可为儿子高兴。

(7) may as well as还是…好了e.g. You may as well as give him the letter.

(8) may……but….表转折

(9) cannot … too / enough 表示 “无论怎么……也不算过分”、“越……越好”

(10) had better do dth 最好做某事。

1. That man has a bad reputation. You _had better not have_____ anything to do with him.1991

A. had better not have B. have better have C. have better not have D. had better not to have

(11) 其它

1. I _was to have finished___ writing the paper as scheduled, but my mother’s illness interfered. I hope you will excuse me.1993

A.am to have finished B.was to have finished C.was to finish D.ought to finish

2. They _do not have to leave___ a tip if the service is poor. (1990)

A. don’t have to leave B. must no leave C. can not leave D. do not leave

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