高考英语复习语法知识专题讲解
专题九情态动词
情态动词本身有一定的词义，但需和其他动词一起构成谓语，除ought, ud外，情态动词后面接动词原形。情态动词中have to可以用have got to 代替；need,dare也可用实意动词；ud to 有两种否定形式：ud not to和did not u to.
can, could 表示具有某种能力，指有能力做某事He could swim when he was five.
By the age of ven he could write beautifully.
表示请求和允许，和may相近；
口语中可用could表示委婉语
气，但回答时仍用can
－Could/Can I u your pen?
－Yes,of cour you can.
泰州桃园
Could I ask for your reaction to this policy?
表示推测，常用于否定句和疑问句中
Mike can't have found his car, for he came to work
by bus this morning
I think the work can be completed ahead of time. 表示“有时也会” It can be quite windy there, especially in spring. cannot but do sth.表示“只好，不得不” Father cannot but agree with his daughter's
opinion.
淘宝商城鞋can't help doing sth. 表示“禁不住做某事” I can't help feeling sorry for the poor man.
The film is so impressive that we can't help crying.
be able to be able to 可以有多种时态，如：将来时
明辨是非的意思（will be able to), 完成时（have/has/had
been able to)
I will be able to speak French in another few
months.
I have been able to swim since I was 5.
be able to 侧重通过努力成功做成某事的
能力
He said he could swim across the river.
(指本身具有这种能力）
At last he was able to swim across the river.
(指通过努力做到了）
表示允许、许可或征求允许，否定回答
－Might/May I smoke in this room?
－No, you mustn't.
may, might 时要用 mustn't; might 比may 语气委婉－May/Might I take this book out of the room?
－Yes, you can. (No, you mustn't.)
表示可能性，might比may可能性更小
I think the trip may give me time to calm down.
An active volcano may explode at any time.
Don't go too far afield or we might lo you. may/might as well do sth.“不妨做某事，
还是做某事为好”
Everything is ready. We might as well start now.
will, would 表示意志、决心或愿望We will do our best to save the child.
I told her to stop crying, but she just wouldn't
英语三级listen.
用于第二人称，表示请求、建议等Will/Would you plea post the letter for me?
Won't you take off your coat?
will表示“总是，惯于”；would表示过
去的习惯，意为“过去常常”
When he was a child, he would often go skiing.
He would sit there for hours sometimes doing
nothing at all.
表示推测或猜想This will be the hou you're looking for.
I think he would accept the invitation.
shall 用于第一、人称的疑问句中，表示征求
对方的意见或请示
Shall I clean the desks one by one?
用于第二、人称的陈述句，表示说话者
的命令告、许诺等语气
He shall return that book tom
I shall think it over and let you know my idea.
You shall fail if you don't work harder.(警告）
用于第三人称，在条约、规定、法令等
文件中表示义务或规定，意为“应该，
必须”
Candidates shall remain in their ats until all the
papers have been collected.
Persons under 18 shall not be employed in night
work.
should, ought to 表示“应该”，用于表示现在或将来的责
任或义务：还可表示推测，指有一定依
据的推测
We should/ought to help each other and learn from
each other in our work.
We ought to go and e Mary tomorrow, but I don't
think we will.
It ought to be a fine day tomorrow morning.
should 还可表示惊讶，意为“竟会，居然” It's strange that he should be abnt.
It ems unfair that this should happen to me.
must, have to must 强调主观看法，表示“必须”，have
to 强调客观需要，意为“不得不”
Yesterday morning I told my father that I must call
on a friend.
You have to wear uniform on duty, don't you?
must表示“偏要，非得”等含义，这种用
法常用于疑问句、条件句中
Must you waste so much time?
Must you make so much noi?
Why must you always interrupt me?
We were ready to leave, but the baby must catch
cold.
mustn't意为“不许，禁止”；若表示“没
有必要，不必”时，用needn't或don't
have to
That car is my property;you mustn't u it without
my permission.
You mustn't drive into a street with a“No
Entry"sign.
You needn't talk to anyone if you don't want to.
You don't have to worry about me. I'm a good
swimmer.
must 表示推测时，仅用于肯定句，但在
反意疑问句中，其后面反问部分取决于
must后面的动
词形式
You must be a newcomer, aren't you?
She must have been very young when she got
married.
It must be your mother who you are thinking of.
need 表示“需要，必须”，常用于疑问句和否
定句中；肯定回答用must, 否定回答用
needn't
You needn't have the bike repaired right away.n
－Need I go back to Xiamen after I visited
Fuzhou?
－Yes, you must./No, you needn't.
dare 主要用于否定句、疑问句以及条件句
中，有过去式形式dared
－Dare she tell him what she thinks about him?
－She daren't say anything.He will only shout at
her. "How dare you speak to me like that?"
ud to “过去常常”，含有今昔对比的意味，表
示过去习惯的动作或状态现在已结束，
而would表示过去反复发生的动作，但
不含对比意味。水星的卫星
He ud to get up at six every morning.
He would get up at six every morning and had a
walk in the forest then.
had better would better had better/would better 表示“最好···”
would better 还可表示“宁愿，宁可”
You had better go to the factory and have a look.
I would better die before asking him for help.
情态动词＋have done must have done 用在肯定句中，表示对
过去情况的肯定推测，语气坚定
It must have rained last night, for the road is wet.
Tom must have taken your dictionary by mistake. can't have done 表示对过去情况表示否
定的推测，是must have done的否定形
式
Mr.Smith can't have gone to Beijing, for I saw him
in the library just now.
Mary can't have stolen your money. She has gone
home.
could have done 用于肯定句，表示过去
本能完成某事但事实上并没有完成，意
为“本来能够做”
教育论文网He could have pasd the exam, but he was too
careless.
He could have bought the car, but soon his
company went bankrupt.
may/might have done 表示过去可能发生
某事，意为“可能······, 或许······”；might
have done还可表示“本可能做某事”
－What has happened to George?
－I don't know. He may have got lost.
She might have achieved greater progress, if you
had given her more chances.
should have done 表示“过去本应该做某
事而没有做”
Tom, you are too lazy. The work should have been
finished yesterday.
成例If I knew she was short of money, I should have
lent her some.
shouldn't have done sth.表示“过去本不该
做某事而实际上做了”
Look, Tom is crying, I shouldn't have been so harsh
on him.
I don't think you have changed at all! Xiao Li
shouldn't ave failed recognize you.
needn't have done 表示“过去本没有必要
做某事而实际上做了”
I needn't have bought so much wine-only five
people came.
As you worked late yesterday, you needn't have
come this morning.
2021高考英语语法高考英语语法【【情态动词情态动词】】易错点对点训练30题
I.高考真题诊断·单句语法填空
1. I can't find my pur. I_______have left it in the supermarket yesterday, but I'm not sure.
2.In today's information age, the loss of data_______ cau rious problems for a company.
3. My room is a mess, but I _______ clean it before I go out tonight. I can do it in the morning.
4. George _______（go)too far. His coffee is still warm.
5. I needn't_______（worry)before I came to the new school,for my classmates here are very friendly to me.
【答案详解】
1. could/might/may 解析：句意：我找不到我的钱包了。我可能昨天把它落在超市了，但我不确定。空处
表示对过去事情的推测，且根据题干中的I'm not sure 可推知，此处表示不确定的推测，故用could/might/may 意为“可能”。
互为倒数2. can 解析：句意：在当今这个信息时代，对于一个公司来说，数据的丢失可能会造成严重的后果。根
据句意可知，语境要体现的是一种客观的可能性，且cau 为动词原形，因此can 符合语境。
3. needn't 解析：句意：我的房间很乱，但是在今晚我出去之前不需要打扫，我可以明天早晨再打扫。needn't 意为“不需要，不必”。
4. can't have gone 解析：句意：乔治不可能走太远，他的咖啡仍是温的。can't have gone 意为
不可能走（远）”，是对过去情况的否定推测，符合语境。
5. have worried 解析：句意：我来新学校之前本没有必要担心的，因为在这里我的同学对我非常友好。needn't have done 意为“本没有必要做某事而实际上已经做了”。 II.精选典题精选典题情态动词情态动词情态动词专题对点训练专题对点训练·单句语法填空
6.If the new safety system (bring) into u, the accident would never have happened.
7.When you phoned me, I was having a meeting; how I wish I (answer) your call.
8.As the deadline is drawing near, no one leave with his own work uncompleted.
