高考英语语法复习专题精讲精练 情态动词和虚拟语气.doc

一、情态动词
情态动词表示说话人的语气和情绪,本身词义不全,不能单独作谓语,后面必须与动词原形一起构成谓语。情态动词没有人称和数的变化,有的情态动词有过去式。常见的情态动词有can, could, may, might, must, have to, shall, should, will, would, ought to, need, dare等。
重点要掌握下列内容
情态动词
重点知识
举例
can
在否定句、疑问句和感叹句中,表示怀疑、惊异、不相信的态度。
Can it be true? 难道这是真的?
You can't be serious! 你怕不是在开玩笑吧!
Oh, dear, what on earth can this mean?
哎呀,亲爱的,这究竟是意味着什么?
表示“经过努力后终于能……”用be able to
The fire spread the building quickly but everybody was able to ,但大家都逃了出来。
注意:be able to比can有更多的形式变化
When he grows up, he will be able to support his family.
他长大后就能养家了。
Frank is ill. He hasn't been able to go to school for one ,已经一周没去上学了。
“cannot (can't)…too/over/enough”。
表示“无论怎么……也不(过分)”,用来加强语气
You can not be too careful.
你无论怎么小心都不为过(你越小心越好)。
can not but do sth. 不得不;只好
I can’t but choose to 。
may和might
惯用形式 may (might)as well+动词原形:不妨做……
If that is the case, we may as well try.
如果情况是这样的话,我们不妨试试看。
表示祝愿may而不用might。采用部分倒装语序:may+主语+动词原形+……!
May the friendship between our two peoples last forever!
祝愿我们两个民族的友谊源远流长!
may或might可和as well连用,表示“建议”,译为“还是……的为好”
You may as well keep a certain distance from that mad man. 你们还是离那疯子远点为好。
You might as well go home now.
你还是现在回家为好。
must
must 还表示主语主观的坚持,有“偏偏, 偏要,一定要”之意
If you must know how old I am, I tell you that I’m twice my son’s age.
如果你一定要知道我多大年龄的话,我告诉你我是儿子年龄的两倍。
must表示推测时的否定式是“can’t”翻译为“不可能”
Michael ______be a policeman, for he’s much too short.
A. needn’t B. can’t C. wouldn’t D. mustn’t
would 和used to
used to表示过去的某种****惯,现在已经没那样的****惯了;would 表示过去有某种****惯,不与现在对比
We would sit in the yard every evening and listen to his story. (过去会这样,不与现在对比)
We used to sit in the yard every evening and listen to his story.(过去是这样的,但现在不这样了)
表示过去的状态,只能用used to,不能用would
There used to be a park here.
这儿过去有个公园。(言下之意:现在没有了)
shall和should
于第一人称:征求对方的意见
What shall we do this evening?我们今天晚上要做什么?
shall用于第二、三人称表示“警告、命令、允诺、威胁”等
You shall fail if you don’t work harder.
你不更加努力工作,你就不会成功。(警告)
You shall have the