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【复习卡】
08 情态动词和虚拟语气
I.情态动词基本用法
情态动词 用 法 否定式 疑问式 简答式
can 能力（体力，智力，技能） can not / cannot /can’t do
允许或许可（口语中常用） Yes,…can.
Can…do…?
could 可能性（表猜测，用于否定 couldn’t do No,…can’t.
句或疑问句中）
May…do…? Yes,…may.
may 可以（问句中表示请求） may not do
No,…mustn’t/can’t.
可能，或许（表推测）
Yes,…might
might 祝愿（用于倒装句中） might not do Might…do…?
No,…might not.
必须，应该（表主观要求） Yes,…must.
must 肯定，想必（肯定句中表推 must not/mustn’t do Must…do…? to. No,…needn’t/don’t
测） have
只好，不得不（客观的必 Yes,…do.
have to don’t have to do Do…have to do…?
须，有时态和人称的变化） No,…don’t.
应当（表示义务责任，口语 ought not to/oughtn’t to Yes,…ought.
ought to Ought…to do…?
中多用should） do No,…oughtn’t.
用于一三人称征求对方意见
Yes,…shall.
shall 用于二三人称表示许诺、命 shall not/shan’t do Shall…do…?
No,…shan’t.
令、警告、威胁等
应当，应该（表义务责任）
should should not/shouldn’t do Should…do…?
本该（含有责备意味）
will 意愿，决心 will not/won’t do
Yes,…will.
请求，建议，用在问句中 Will/Would…do…?
would would not/wouldn’t do No,…won’t.
would比较委婉
敢（常用于否定句和疑问句 Yes,…dare.
dare dare not/daren’t do Dare…do…?
中） No,…daren’t.
需要,必须（常用于否定句和 Yes,…must. No,…
need need not/needn’t do Need…do…?
疑问句中） needn’t.
Yes,…used.
used not/usedn’t/usen’t
Used…to do…? No,…use(d)n’t.
used to 过去常常（现在已不再） to do
Did…use to do…? Yes,…did.
didn’t use to do
No,…didn’t.
II.情态动词的重点知识
A computer_____think for itself; it must be told
what to do.
表示能力的情态动词用can/could
A.can’t B.mustn’t C.may not
D.might not
①—Could I call you by your first name? —
Yes, you______
表示“能 表示许可时用may/might ,can/could 都可以，但在问句中用
A.will B.could C.may D.might
力 、 许 could…?或might…？ 以使口气委婉客气，其回答一定要用
② Johnny, you_____play with the knife,
可”的can can 或may，以使回答口气明确（must表示一定，必须，
you_____hurt yourself.
和may mustn’t表示禁止，不许可）。
A.won’t/can’t B.mustn’t/may
C.shouldn’t/must D.can’t/shouldn’t
The fire spread through the hotel very quickly but
在肯定句中could不可以用来表示过去某一特定场合的能力， everyone_____get out.
而要用was/were able to。 A.had to B.would C.could
D.was able toPeter______come with us tonight, but he isn’t very
sure yet.
在肯定句中都可以用来表示可能。在含义上 must语气最肯 A.must B.may C.can
定,may表示的是事实上的可能性。 D.will
而can表示的是逻辑上的可能性：
表示“推 Mary is in poor health. She can be ill at any times.
断 、 判 Michael______be a policeman, for he’s much too
断”的can 在否定句中只能用 can 和 may。所以 can’t 时用以代替 short.
may,must mustn’t，语气比may更肯定。中文可以翻译为不可能。 A.needn’t B.can’t C.should
D.may
He may be very busy now. Can he be very
busy now?
在疑问句只能用can，不能用may和must。
He must be very busy now. Can he be very
busy now?
need need作为情态动词只有一种形式，只用于否定句和疑问句。
If he dare come,I will kick him out. I don’t know
whether he
dare作为情态动词用时有两种形式：dare和dared两个词形，
dare say.
dare 除了可以用于否定句和疑问句外，还可以用于条件从句或表
注意:He doesn’t dare(to)answer the question.（否
示怀疑的句子中。
定句）
Does she dare(to)enter the dark room?（疑问句）
用于第一人称：征求对方的意见。 What shall we do this evening?
You shall fail if you don’t work harder. 警告
shall
用于第二、三人称：警告、命令、允诺、威胁等。 He shall have the book when I finish reading.允诺
He shall be punished.威胁
You should(ought to) go to class right away.
should 劝告、建议、命令、应该做、道义上的责任。
I should(ought to) help him because he is in trouble.
请求、建议，would比will委婉客气。 Would you pass me the book?
I will never do that again.
表示意志、愿望和决心。
They asked us if we would do that again
will/would During the vacation he would visit me every week
would可表示过去反复发生的动作或某种倾向。
The wound would not heal.（伤口老是不能愈合）
It would be about ten when he left home.
would表示估计或猜想。
What would she be doing there?
You could have done better, but you didn’t try your
could+have done：本可以做而实际上未能做。
best.
cannot+ have done：表示对现在或过去行为的否定推测。 He cannot have been to that town.
can+主语+ have done：表示对过去行为的怀疑或不肯定（用
Can he have got the book?
在疑问句中）。
He may not have finished the work.
might(may)+ have done：对过去发生的行为不太肯定的推
If we had taken the other road, we might have
测。
arrived earlier.
must+ have done：对过去发生的行为肯定的推测。 You must have seen the film.
情态动词
其否定式为：cannot have done。 You cannot have seen the film.
+have
You needn’t have watered the flowers,for it is going
done 的 用
to rain.
法
注意：didn’t need to(have to)do：
needn’t+ have done：本来不必要做的而实际上又做了。
没有必要做而实际上也没有做
I didn’t need to clean the windows.My sister did it 2
hours ago.
You should have started earlier, but you didn’t.
She shouldn’t have taken away my measuring tape,
should(ought to)+ have done：本来应该做而实际上又没有
for I worked to use it.
做。其否定形式表示某中行为不该发生却发生了。
注意：He should have finished the work by now.
（表推测）
III.虚拟语气
类 别 用 法 例 句从句动词：过去式（be用were）
与现在事实相反 If he were here, he would help us.
主句动词：should/would/could/might+do
If引导的 从句动词：had+done
与过去事实相反 If I had been free,I would have visited you.
条件从句 主句动词：should/would/could/might+have+done
从句动词：过去式/should+动词原形/were+to do If it should rain tomorrow, we would not go
与将来事实相反
主句动词：should/would/could/might+动词原形 camping.
①Should he come ,tell him to ring me up.
** 错误的表达式 **Were I you,I would not
省略if的虚 将虚拟条件从句中的were，had,should放到主语之前，构成主谓倒
do it.
拟条件句 装
** 错误的表达式 **Had I been free,I
would have visited you.
①If he had listened to me, he would not be
in trouble now.
** 错误的表达式 **If he had told me
不同时间的虚拟：各遵守各的规则
yesterday,I should know what to do now.
混合虚拟条 ** 错误的表达式 **If I were you, I would
件句 have gone to her birthday party.
① He could have passed the exam,but he
wasn’t careful enough.
虚拟与陈述的混合：各遵守各的规则
** 错误的表达式 **You should have come
earlier.The bus left a moment ago.
---But for your timely warning,we ______
into great trouble.
---You know we’re friends.
but for+名词表示虚拟条件
A. would get B . must have got
C. would have got D. can’t have
got
Without the air to hold some of the sun's heat,
without+名词表示虚拟条件
the earth at night would be freezing cold.
It would be only partly right to follow in this
动词不定式表示虚拟条件 way.
如果用这种方式，仅仅对了一半。
句子或主句中的谓语动词的 Having known in time ,we might have
含蓄虚拟 现在分词表示虚拟条件 形式视具体情况而定。这是 prevented the accident.要是及时得知的话，
条件句 考查考生应变能力的最佳试 我们也许能阻止这场事故。
题。 Given more attention, the tree could have
grown better.
过去分词表示虚拟条件
如果多留心的话，这树本来可以长的更
好。
I was too busy at that time.Otherwise,I would
副词otherwise表示虚拟条件 have called you.我当时太忙，否则我就给
你打电话了。
He _____fatter but he eats too little .
A. would become B. would have
连词but连接的句子表示虚拟条件 become
C. must become D. must have
become
①与现在事实相反
as if/as though引导的状语从句中动词用did或had＋done或would／ He talks as if he knew where she was．
could／might＋do。 ** 错误的表达式 **与过去事实相反
注意：as if/as though引导的状语从句中也可以用陈述语气： He talks about Rome as if he had been there
其它 当说话者认为所述的是真实的或极有可能发生或存在的事实时： before.
状语从句 It sounds as if it is raining．听起来像是在下雨。 ** 错误的表达式 **与将来事实相反
He talks as if he is drunk．从他谈话的样子来看他是醉了。 He opened his mouth as if he would say
something.
in order that/so that引导的状语从句中动词用 can/could/may/ might/
Turn on the light so that we can see it clearly.
would等+do
宾语从句 demand, suggest, order, insist后接的从句中动词为should+do He suggested that we not change our mind.I wish I could be a pop singer.
wish后的从句中分别用过去式，过去完成式和should/would+do表示
I wish I would have gone to Shanghai
与现在，过去和将来情况相反
last month.
在It is necessary / important / strange that…
It is strange that such a person should be our
主语从句 It is suggested / demanded/ ordered / requested that…等从句中，
friends.
谓语动词用should+do
It is time that…句型中动词用过去式或should+do It’s high time that we left/should leave.
其它
would rather所接的从句中动词用过去式或者过去完成式 I would rather you stayed at home now.
句型中
If only句型中动词常用过去式或者过去完成式，表示强烈的愿望 If only our dream had come true!
