专题十四 情态动词和虚拟语气 课件（共41张） —2026届高考英语二轮复习

(共41张PPT)
专题十四 情态动词和虚拟语气
2026届高考二轮专题复习
考情分析
01
ENGLISH
高频考点：
1. 情态动词的基本用法
2. 虚拟语气的基本用法
3. 虚拟语气的特殊用法
01
考情分析
情态动词和虚拟语气是历年高考的考点。近几年新高考对情态动词和虚拟语气的考查主要集中在语法填空、阅读理解等，以情态动词和虚拟语气的基本用法为主。
知识点讲解
02
1. can & could
（1）表示能力，但could主要指过去的能力。表示“过去有能力做成某事”时通常用was/ were able to
The little boy can speak two foreign languages.
这个小男孩会讲两种外语。
Could the girl read before she went to school
这个女孩上学前识字吗
Everyone was able to escape when the fire broke out.
起火的时候大家都能逃生。
02
知识点讲解
一、情态动词
（2）表示可能（理论上或是逻辑判断上，并不涉及此事真的发生），常译为“往往会，有时候可能会”，常用于肯定句中
Although you can find bargains in London, it's not generally a cheap place to shop.
虽然你有可能在伦敦买到便宜的东西，但通常而言这不是个买便宜东西的地方。
（3）表示请求和允许。在问句中could语气比can要委婉
Could I have a word with you It won't take long.
我能和你说句话吗？不会占用你很长时间。
You can go back home now.
你现在可以回家了。
02
知识点讲解
一、情态动词
（4）表示惊异、怀疑、不相信等态度。主要用于否定句、疑问句或感叹句中
How can you be so careless
你怎么能这么粗心？
（5）表示推测，常用于否定句和疑问句中，语气较强
He can't be in the classroom; the light is not on.
他不可能在教室里；灯没亮。
Why are your eyes so red You can't have slept well last night.
你的眼睛为什么红红的？你昨天晚上一定没有睡好。
My favourite book is missing. Who could have taken it
我最喜欢的书丢了，谁会把它拿走呢？
02
知识点讲解
一、情态动词
（6）cannot/ can never...too/ enough...表示“再……也不为过”
You can never be too careful when driving a car.
开车的时候，你再怎么小心都不为过。
While you are doing your homework, you can't be careful enough.
写作业时，你再怎么仔细也不为过。
（7）cannot but do sth./ cannot help but do sth./ cannot choose but do sth.表示“不得不/ 只好做某事”
You cannot choose but go with me.
你只能跟我走。
02
知识点讲解
一、情态动词
2. may & might
（1）表示请求、允许、许可，might比may语气委婉
You may use my bike.
你可以用我的自行车。
（2）表示推测，常用于陈述句中，语气比较弱，把握性不大。might语气比may还要弱
We might be going to Spain on holiday this year.
今年我们或许会去西班牙度假。
I thought we might go to the zoo on Saturday. 我觉得周六我们可以去动物园。
02
知识点讲解
一、情态动词
（3）may/ might as well+动词原形，意为“最好，倒不如……"
You may/ might as well do it at once.
你最好立刻开始做。
（4）may well+动词原形，意为“完全能，很可能”
He may well be late for class.
他上课很可能迟到。
（5）may用于祈使句中，表示祝愿
May you return in safety.
祝你安全归来。
02
知识点讲解
一、情态动词
3. must
（1）表示主观上的“必须，应该”，其否定形式mustn't表示禁止
对比：have to表示客观上的“不得不”，可用于各种时态。
以must开头的问句，其否定回答用needn't或don't have to。
-Must I clean the dining room at once —我必须马上打扫餐厅吗？
-No, you needn't. / No, you don't have to. —不，你不必。
Students mustn't play with mobile phones in class.
学生课上不准玩手机。
I had lost my key, so I had to wait outdoors.
我丢了钥匙，所以不得不在门外等。
02
知识点讲解
一、情态动词
（2）表示“非要，偏要”做某事，表达出说话者的一种不满情绪
Why must you be talking so loudly when others are sleeping
别人都在睡觉，为什么你偏要这么大声说话？
-Can I smoke here
-No. Go to the smoking section, if you must.
—我能在这里抽烟吗
—不能，如果你非要抽烟的话，就去吸烟区吧。
（3）表示对具体事情的推测，意为“一定，肯定”，语气较强，只用于肯定句中
Since nobody gave him any help, he must have done the research on his own.
既然没有人给他任何帮助，那他一定是独自完成的这项研究。
02
知识点讲解
一、情态动词
4. shall
（1）用于第二、三人称的陈述句中，表示命令、许诺、警告、强制、威胁、决心等；此外，颁布法律、规定时也用shall
You shall do as your father says.
你要按照你父亲说的那样做。
One of our rules is that every student shall wear school uniform while at school.
我们规定中的其中一项是：每位学生在校期间都要穿校服。
（2）用于第一、三人称的疑问句中，表示说话人征求对方的意见或向对方指示
Shall the man standing outside have a try
站在门外的那个人可以试试吗？
02
知识点讲解
一、情态动词
5. should & ought to
（1）表示义务，常意为“应该”，用于各种人称。ought to的语气比should强烈
Parents should/ought to take good care of their babies.
父母应该照看好他们的孩子。
（2）should表示推测，意为“可能，（按道理）应该”，多指对未来合乎理想的情况或结果的一种期盼
It's nearly 8 o'clock. He should be here at the moment.
快八点钟了。此刻他应该在这儿了。
02
知识点讲解
一、情态动词
（3）should表示惊讶、意外等，意为“竟然，居然”
You should wear slippers in the classroom.
你竟然在教室里穿着拖鞋。
It's funny that we should be living in the same block of flats.
我们竟然住在同一幢公寓里，真有趣。
（4）用在if条件句中，should表示可能性很小的一种虚拟语气
If I should see him, I would tell him the news.
如果我见到他，我就告诉他这个消息。
02
知识点讲解
一、情态动词
6. will & would
（1）用于各种人称，表示主语的意愿和意志
He will take you home.
他愿意送你回家。
（2）用于第二人称的一般疑问句，表示请求
Will/ Would you go with me
你愿意和我一起去吗？
（3）will用来叙述目前的习惯；would表示过去的习惯
He would get up early when he lived in the country.
他住在乡下时总是早起。
02
知识点讲解
一、情态动词
7. need & dare
（1）实义动词
有人称和数的变化，可用于肯定句、否定句或疑问句中，构成否定句或疑问句时要用助动词do，does，did
He said it as loudly as he dared.
他壮着胆子大声地说了出来。
（2）情态动词
没有人称和数的变化（dare可以有过去式dared），直接接动词原形，主要用于否定句和疑问句中，构成否定句和疑问句时不用助动词
Dare you say so in public
你敢在公共场合这么说吗？
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知识点讲解
一、情态动词
8. “情态动词+have done”用法
（1）could have done的疑问或否定形式表示对过去发生的行为表示怀疑或不肯定，其中couldn't have done多用于语气强烈的否定，意为“过去不可能做过”。could have done在肯定句中表示“本来能做但却没做”
The accident could have been avoided; the driver couldn't have slowed down.
这事故本来是可以避免的；司机肯定没减速。
（2）may/ might have done表示对过去行为的推测，意为“可能做过”。might 所表示的可能性比较弱，此外might have done 还可表示“本可能做而实际上未做”，含有轻微的责备语气
You might have given him more help, though you were busy with your work.
你本来可以给他更多的帮助，尽管你工作很忙。
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知识点讲解
一、情态动词
（3）must have done表示对过去行为的推测，意为“一定，想必做过”，语气十分肯定
It must have rained last night, as the ground is wet.
昨晚一定下雨了，因为地面是湿的。
（4）should/ ought to have done用于肯定句时，表示“本该做某事而实际上未做”；用于否定句时，则表示“不该做某事反而做了”
-Sorry, Mum! I failed the job interview again.
-Oh, it's too bad. You should have made full preparations.
—对不起，妈妈，我这次工作面试又失败了。
—噢，太糟糕了。你本来应该进行充分准备的。
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知识点讲解
一、情态动词
（5）needn't have done表示“本来不必做某事而实际上却做了”
I actually needn't have bought so much food—only three people came.
我实际上不必买这么多食物——只有三个人来了。
（6）had better have done用于事后的建议，含轻微责备的口吻，意为“当时最好做了某事”
You had better have done that.
你最好把那件事做完。
I had better have started earlier.
我要是早点起程就好了。
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知识点讲解
一、情态动词
（7）would rather have done表示“宁愿当时做某事”，其否定形式would rather not have done sth.表达相反的含义，两者都含有“后悔”之意
I would rather have taken his advice.
我宁愿当时接受了他的建议。
（8）would like/love to have done sth.表示“过去愿意做某事但未做成”
I would love to have gone to the party last night, but I had to work extra hours to finish my report.
我昨天晚上本想去参加聚会，但我不得不加班写完报告。
02
知识点讲解
一、情态动词
9. 几组易混情态（助）动词
（1）would & used to
① would表示过去反复的动作，常与every day，often frequently等连用
When he was abroad，he would often read as many books as possible.
在国外时，他总是尽可能多地读书。
② used to表示过去的状态、习惯，但现在已经不存在
She doesn't get up so early as she used to.
她不像以前那样起得那么早了。
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知识点讲解
一、情态动词
（2）could & was able to & could have done
① could表示过去的能力，但不代表是否做
He could ride a bicycle at the age of 5.
五岁时他就会骑自行车了。
② was able to表示过去有能力并且成功地做了，相当于managed to do sth.
The fire spread very quickly but everyone was able to get out.
火蔓延很快，但大家都成功地逃了出来。
③ could have done表示过去本有能力做某事，但没有做
The resources at our disposal could have been better utilized.
我们所掌握的资源本来可以利用得更好，获得更高的效益。
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知识点讲解
一、情态动词
（3）must & have to
① must多表示由于主观需要或责任感而有必要、有义务去做某事，意为：必须
I must clean the room because it is too dirty.
由于房间太脏了我必须打扫。
② have to表示为客观条件、环境所迫而做某事，意为“不得不”
He has to leave school because he can't afford his schooling.
因为他付不起学费，所以不得不辍学。
02
知识点讲解
一、情态动词
（4）didn't need to do & needn't have done
① didn't need to do表示过去没必要做某事，不强调是否做
I didn't get up that early yesterday，for I didn't need to.
昨天我没那么早起床，因为没必要。
② needn't have done 表示过去没必要做某事，但做了
I needn't have got up that early yesterday but I had to because the dog barked all the time.
昨天我本不必那么早起床，但是由于狗一直叫，所以我不得不起床。
02
知识点讲解
一、情态动词
1. 虚拟语气用于非真实条件句中
（1）表示与现在事实相反，从句谓语用“过去式（be动词用were）”，主句谓语用“would/ should/ could/ might+动词原形”
If I were you, I would seize the chance.
如果我是你，我就会抓住这个机会。
（2）表示与过去事实相反，从句谓语用“had+过去式”，主句谓语用“would/ should/ could/ might+过去分词”
If you had taken my advice, you wouldn't have failed.
如果你听了我的建议，你就不会失败。
02
知识点讲解
二、虚拟语气
（3）表示与将来事实相反，从句谓语用“① 过去式；② should +动词原形；③ were to+动词原形”，主句谓语用“would/ should/ could/ might+动词原形”
If he shouldn't come tomorrow, we would put off the meeting.
如果他明天不来，我们就推迟这个会议。
注意：
（1）当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，这种句子被称为“错综时间条件句”，动词的形式要根据它所表示的时间做出相应的调整
If you had followed my advice you would be better now.
如果你听了我的建议，你现在就好一些了。
02
知识点讲解
二、虚拟语气
（2）在if引导的非真实条件从句中，谓语动词含were，had，should，可将if省略，但需将were，had，should提到主语之前
If I were at school again, I would study harder.
→ Were I at school again, I would study harder.
如果我还有上学的机会，我会更加努力学习。
（3）有时假设的条件并不总是通过if引导的条件从句表达，而是隐含在某些词、短语或上下文中，此种句子为“含蓄条件句”，常见的词或短语有：without，in case，but for，for fear that，otherwise等
Without your help, we couldn't have finished the work ahead of time.
没有你的帮助，我们不可能提前完成这项工作。
02
知识点讲解
二、虚拟语气
2. 虚拟语气在wish，if only(=how I wish)，as if后的从句中
（1）从句谓语动作与主句谓语动作同时发生，从句谓语用“过去式（be动词用were）”
If only/How I wish I were a flying bird!
我多希望我是一只会飞的鸟儿啊！
He looks as if he were an artist.
他看上去好像是名艺术家。
（2）从句谓语动作先于主句谓语动作发生，从句谓语用“had+过去分词”
She speaks English so fluently as if she had stayed in America for a long time.
她说英语如此流利，好像她在美国待过很长时间似的。
02
知识点讲解
二、虚拟语气
（3）从句谓语动作后于主句谓语动作发生，从句谓语用“would+动词原形”
He learns English so hard as if he would go to the U.S.A.
他如此努力学习英语，就好像他要去美国。
注意：
当句子所叙述的是真实的或极有可能发生的或存在的事实时，as if从句要用陈述语气。
It seems as if it is going to rain.
天似乎要下雨。
He walks as if he is drunk.
他走起路来像是醉了。
02
知识点讲解
二、虚拟语气
3. 虚拟语气用在主句含“坚持、命令、建议、要求”的名词性从句
一坚持：insist
二命令：order, command
四建议：advise, suggest, propose, recommend
四要求：require, request, demand, ask
谓语动词用“should+动词原形”（should可以省略）
He suggested that we (should) start off early the next day.
His suggestion was that we (should) start off early the next day.
他建议我们第二天早点出发。
It was suggested that we (should) start off early the next day.
人们建议我们第二天早点出发。
02
知识点讲解
二、虚拟语气
4. 虚拟语气用在“would rather + that从句”中
（1）表示对现在或将来的虚拟，从句谓语用“过去式（be用were）”
I'd rather you came with us.
我倒愿意你和我们一块儿去。
I'd rather they didn't hear of the news.
我宁愿他们没有听到这个消息。
（2）表示对过去的虚拟，从句谓语用“had+过去分词”
I'd rather I had not told him the bad news.
我宁愿没有告诉过他那个坏消息。
02
知识点讲解
二、虚拟语气
5. 虚拟语气用在“It is (high) time + that从句”中
that从句谓语用“过去式或should+动词原形”，且should不能省略
It is (high) time that you went/should go to school.
你们该去上学了。
6. 虚拟语气用在“It is necessary等+that从句”中
在“It is necessary/ important/ vital/ surprising/ strange/ natural/ a pity/ essential等+that从句”中，that从句谓语动词用“should+动词原形”，should可以省略。should意为“竟然”。
It is strange that the meeting (should) be put off till next week.
那个会议竟然被推迟到下周，真奇怪。
02
知识点讲解
二、虚拟语气
7. 虚拟语气用在目的状语从句中
由in case，for fear that，in order that，so that等引导的目的状语从句，其谓语动词用“would/ should/ could/ might+动词原形”表示虚拟
They left early for fear that they would meet him.
他们动身很早以免和他碰面。
I gave you a map so that you wouldn't get lost!
我怕你迷路，给过你一张地图！
The sun is shining, but I'll take an umbrella just in case it should rain.
现在是晴天，但我还是带上雨伞以防万一。
02
知识点讲解
二、虚拟语气
典例剖析
03
03
典例剖析
1. _________ I live out of town, I would take up gardening as a hobby.
答案：Should 解析：考查虚拟语气。句意：要是我住在城外，我会把园艺当作一种爱好。这是一个虚拟语气的句子，表示不太可能实现的愿望，在虚拟语气中，句首Should+主语+动词原形，常用来表示与现在事实相反的假设。故填Should。
2. If I _________ (know) more about first aid, I could have helped them then.
答案：had known 解析：考查虚拟语气。句意：如果我当时知道更多的急救知识，我那时就能帮助他们了。if引导了虚拟条件句，根据主句中的"would have helped"可知，本句话是与过去事实相反的假设，所以从句中用过去完成时态，即"had done"的结构。故填had known。
03
典例剖析
3. It's surprising that James insisted that she _________ (come) downtown to explain this.
答案：come/should come 解析：考查虚拟语气。句意：令人惊讶的是，詹姆斯坚持要她到市中心来解释这件事。句中that引导的从句为insisted（坚持要求）后的宾语从句，因此that从句中需使用虚拟语气，即insist +that +should+动词原形，其中should可以省略，主语she与come是主动关系，因此需要使用主动语态，即come或should come。故填come/should come。
03
典例剖析
4. Only when we learn to live in harmony with nature _________ we stop being a threat to wildlife and to our planet.
答案：can/will 解析：考查情态动词。句意：只有当我们学会与自然和谐相处时，我们才能停止对野生动物和我们的星球的威胁。only修饰状语从句位于句首，句子应用部分倒装。在时间状语从句中用一般现在时表将来。根据"Only when we learn to live in harmony with nature"和"we stop being a threat to wildlife and to our planet"可知，此处是指才能停止对野生动物和我们的星球的威胁，应用情态动词can或will表示"能够，会"。故填can/will。
03
典例剖析
5. Remember, however, that you should usually consult different types of sources. That is, you _________ always rely just on the Internet for your research.
答案：shouldn't 解析：考查情态动词。句意：但是，请记住，您通常应该参考不同类型的资料来源。也就是说，你不应该总是仅仅依赖互联网来做研究。根据前文you should usually consult different types of sources. 可知，后文always rely just on the Internet for your research是对前一句的进一步解释，空处应用should的否定形式shouldn't表示"不应该"。故填shouldn't。
变式训练
04
Exercise
1. The doctor advised Vera strongly that she _______________________________ (operate) on at once.
2. If I _________ (be) in your position, I would make a very different decision.
3. If the new safety system _____________ (put) to use, the accident would never have happened.
4. When we worked in the same firm several years ago, we _________ go to the cinema together every weekend.
5. He _________ have finished writing the paper. He hadn't written a single word when I left him fifty minutes ago.
should be operated/be operated
were
had been put
would
can't