2023届高考英语语法复习：助动词与情态动词课件-（31张）

(共31张PPT)
Lecture One
助动词与情态动词
Auxiliary Verbs and Modal Verbs
动词的分类
根据在句中的功能，动词可以分为：
1.实义动词(Notional Verbs)
2.系动词(Link Verbs)
3.助动词(Auxiliary Verbs)
4.情态动词(Modal Verbs)
根据其后是否带宾语，实义动词又可分为：
1.及物动词(Transitive Verbs, Vt.)
2.不及物动词(Intransitive Verbs, Vi.)
助动词（Auxiliary Verbs)
协助主要动词构成谓语动词词组的词叫助动词（Auxiliary Verbs）, 被协助的动词称作主要动词（Main Verbs）。
I don't like coffee.
助动词自身没有词义，不可单独使用。
最基本的助动词有三个：be, do, have.
be,am,is,are,was,were,been,being
have,has, had, having
do,does,did
助动词be,have,do的用法
助动词be主要用来构成各种进行时态和被动语态，及相应的疑问句和否定句。
What were you doing when I called
Smoking is not allowed in this building.
助动词have主要用来构成各种完成时和完成进行时态，及相应的疑问句和否定句。
Have you finished your homework
助动词do主要用来构成疑问句和否定句，以及在动词之前表示强调。
He doesn't care what other people think.
He did know that.
注意：
be动词除了用作助动词外，还可用作系动词，构成系表结构。
He is a dentist.
have和do除用作助动词外，还可用作及物动词。
I have a brother.
What are you doing
助动词will,would,shall,should
除be, have, do外，英语中的助动词还有四个：will, would, shall, should
与be, have,do不同的是，这四个词往往有情态动词的作用，可以说是介于助动词和情态动词之间的词，甚至更接近于情态动词。本讲中将其归入情态动词部分进行讲解。
情态动词（Modal Verbs）
can
could
may
might
must
ought to
shall
should
will
would
半情态动词
need
dare
be able to
have to
had better
所有这些情态动词、半情态动词之后都接不带to的不定式，即动词原形。
除be able to和have to中的be和have有人称、数和时态的变化外，其它情态动词都适用于各种人称，并且没有时态变化。
can, could, be able to
can 可用于表能力，可能性及许可。
He is only four, but he can read.
Can this news be true
Can I smoke here
could 可以作为can的过去式，表过去的能力，或用在间接引语中表过去的可能或许可;还可表示委婉客气地提出问题或陈述看法。
I could swim when I was only six.
Father said I could swim in the river.
Could I use your bike
can 表能力时＝be able to, 但can 强调一贯的能力，be able to 更强调通过努力可以达到的能力,相当于manage to do sth.或 succeed in doing sth.
I can’t swim. But I am sure I will be able to swim through more practice.
The fire spread through the hotel, but everyone was able to get out.
When the boat sank, he was able to swim to the bank.
may, might
may表请求、可以、允许。
You may drive the tractor.
May I come in
Yes, please./Certainly.
No, you can’t.
No, you mustn’t.
No, you’d better not.
may /might 表推测, 可能 ，might 可能性更小.
may be与maybe
maybe是副词，意为“也许，大概”。它通常放在句子的开头，在句子中作状语。
Maybe they won't come here tonight.
Maybe she is happy.
may be是情态动词may加动词原形be构成的，在句中做谓语，意为“可能是、大概是”，后接形容词、介词短语或名词作表语。
She may be at home.
=Maybe she is at home.
You may be right.
=Maybe you are right.
副词 maybe 可单独用作答语，但 may be 不能这样用。如：
A：Do you think he’ll come back
B：Maybe. (Maybe not.)
翻译：你的钢笔可能在你的口袋里。
他可能是个学生。
Your pen may be in your pocket.
Maybe your pen is in your pocket.
He may be a student.
Maybe he is a student.
must, have to
must表必须，必要 ，强调说话人的主观意愿，而have to 更强调客观需要，“不得不”。
I must clean the room.（主观想法）
I have to clean the room.（客观需要）
在回答must引起的问句时，如果是否定的答复，可用don’t have to或needn’t(不必) ，不用mustn’t。
Must I go tomorrow
Yes, please./Yes, you must.
No, you needn’t.
No, you don’t have to.
must be + 表语的结构，通常表示猜测，含有“一定”之意。（只用在肯定句中）
He must be an honest boy.
This must be your room.
have to 有第三人称单数和时态的变化。
She/He/It has to...
They had to ...
They will have to ...
have to的否定和疑问形式必须借助于助动词do来构成。
I have to get up early.
I don't have to get up so early.
Do I have to get up so early
should, ought to
否定形式should not /shouldn’t, ought not to/oughtn’t to
疑问形式直接用should, ought 提问。
你不应该抽这么多烟。
You oughtn't to /shouldn't smoke so much.
我应不应该给她写信？
Should I write to her
Ought I to write to her
should的特殊用法
I find it quite astonishing that he should be so rude to you.
我很惊讶他竟然对你如此无礼。
I can't think why she should have done such a thing.
我不明白她为什么竟然做出这样的事。
should常用在从句中表示一种感彩，可译为“竟然”。
will和would
will,would作为助动词可以用来构成将来时态。
作为情态动词，will/would可以：
1.表示意志，决心或愿望。
Surely we will support all the people in the world in their struggle for peace.
He wouldn't go to see the doctor.
2.表示经常性、习惯性的行为，常译为“总是”。
She will listen to music alone in her room for hours.
He would come to see me when he was in Beijing.
3.用于第二人称作主语的疑问句中，表示对对方的请求，would的语气比will委婉。
Would/will you please tell me the way to the station
4.表猜测，“大概”，“可能”
This will be the book you are looking for.
She would be about 60 when she died.
1.John gets upset when he _______ understand a problem.
2.My pen is out of ink. _________ you let me use yours
3.You'd better take the umbrella with you; it __________ rain.
4.I asked him for the keys, but he _________ give them to me.
5.Her brother died suddenly. She ______ be very sad.
can't
Will/ Would
may/might
would not
must
Exercise: Fill in each blank with a modal verb.
6.—Are you coming to Jeff’s party
—I’m not sure. I _________ go to the concert instead.
7.—Will you stay for lunch
—Sorry, I ________. My brother is coming to see me.
may/might
can't
need
既可以做实义动词，也可以做情态动词。
做实义动词, 有人称和时态的变化：
I need some help. (need sth.)
He needs to get some sleep. (need to do sth.)
His hair needed cutting. (need doing 主动表被动)
此时，否定和疑问都要用助动词do 构成。
I don't need any help./Do you need any help
He doesn't need to get any sleep./ Does he need to...
His hair didn't need cutting./Did his hair need cutting
做情态动词, 后接动词原形，没有人称和时态变化一般只用在否定句和疑问句中：
sb. needn't do sth.,指“不必......”
You needn't wait for me.
She needn't write to him.
He said she needn't write to him.
疑问句可由need直接构成，不必借助于助动词do.
Need she write to him
Need I wait for you
Yes, you must./No, you needn't.
肯定回答用must, 否定回答用needn't.
判断下列句子对错：
She need some paper.
She needs some paper.
Need you any help
Do you need any help
I needn't any help.
I don't need any help.
You don't need wait for me.
You don't need to wait for me.
You needn't wait for me.
(×)
(×)
(×)
(×)
dare 敢......
既可以做实义动词，也可以做情态动词。
做情态动词，无人称变化，只用于否定句和疑问句中,后接动词原形。
Dare you go there alone
I dare not go there alone.
做实义动词，常跟不定式，dare to do sth.，此时疑问和否定须借助助动词。
He dares to speak before a big audience.
Did he dare (to) speak before ...
He doesn't dare (to) speak before...
dare做实义动词时，疑问句和否定句中的不定式符号可以省略。
情态动词＋have done
情态动词完成式的用法主要有两方面的含义：
1.表示对已经发生的情况的推测：
must have done
can't/couldn't have done
may/might have done
2.表示一种虚拟语气：
could have done
should have done/ought to have done
should not have done/ought not to have done
needn't have done
常用在肯定句中，表示对过去发生行为的肯定推测，含有“一定”、“准是”的意思。
She must have studied English before.
她以前一定学过英语。
The road is wet. It must have rained last night.
路是湿的，昨夜一定下过雨。
must have done
表示对过去事情的否定推测，译成“不可能做过某事”。
史密斯先生不可能去北京了，我刚才还在图书馆见过他。
Mr. Smith can't have gone to Beijing, for I saw him in the library just now.
玛丽不可能偷你的钱，她回家了。
Mary can't have stolen your money. She has gone home.
can't have done/couldn't have done
may/might have done
表示对过去发生行为的不太肯定的推测，含有“可能”、“也许是”的意思。
He may have finished his homework.
他也许已经完成了作业。
He might not have settled the question.
他可能尚未解决那个问题。
could have done
表示本来能够完成的动作但没有完成。
You could have completed the task a little earlier.
你本来能够早一点完成任务的。（事实上并没有早一点完成）
I could have passed the exam easily but I made too many stupid mistakes.
我本来可以很轻松地通过考试，但是我犯了太多愚蠢的错误（因此没能通过）。
should have done/ ought to have done表示过去该做而实际上未做的动作或行为；
其否定形式should not have done/ ought not to have done则表示发生了不应该发生的行为。
I should have thought of that.
这一点我本来应当想到的。（但没想到）
They should not have left so soon.
他们本不应该走得这么早。（但已走了）
你本不应该告诉她真相的。
You should not have told her the truth.
should /should not have done
表示过去做了某事，但没有做的必要， 意为“本没必要…”。
You needn’t have woken me up; I don’t have to go to work today.
你本来没必要叫醒我（但已经叫了），我今天不用上班。
She needn’t have come here so early.
她本来不必要来这么早。（但事实上她已经来了）
注意：did not need to do 动作并没发生
Yesterday I didn’t need to get up early, so I got up at 9 a.m.
needn’t have done