资源简介

(共40张PPT)
引入情态动词及其概念，特性介绍
分别讲解can, may， must,have to ,should的用法及分别练习
特殊情态动词need 和dare 讲解
情态动词综合练习
祈使句概念及特点介绍
祈使句三大句式：肯定，否定， let 讲解
祈使句练习
你的英语表达够 吗？
灵活
I go home
Can I go home now
I should go home now.
I must go home now.
I have to go home now.
I may need to go home now.
情态动词为句子注入了‘灵魂’：
它不仅丰富了句子的情感色彩，
更微妙地调控着语气分寸与判断立场等。
什么是情态动词？
情态动词（Modal Verbs）是动词的一种特殊类型，它不表示具体的动作（如“跑”、“吃”），而是用来表达说话者对某个动作或状态的态度、语气或看法。
情态动词特性：
不能单独作谓语，它与行为动词或系动词连用构成谓语。
在句中没有人称和数的变化
否定句在情态动词后+not，疑问句把情态动词提前即可。
常用情态动词
can be able to may
must have to should
ought to dare need
had better
Can 的主要用法
表示能力
表示推测
表示请求
Can表示能力
陈述句
He can speak English.
否定句 can 后面加not
He cannot speak English. = He can’t speak English
疑问句 can 提前 Can he speak English
What language can he speak
can表示请求
Can I sit here
肯定回答 Yes , you can./ Sure. /Of course. 否定回答
No, you cannot.= No, you can’t.
Sorry, I am afraid not.
can表示推测一般只用于疑问句和否定句，不用于肯定陈述句。
否定句中表示100%不可能
Can he be Mr. Lee
He cannot be Mr. Lee. He went to London last week.
他肯定不是Mr. Lee. 他上周去伦敦了。
can在肯定陈述句里表示客观存在性，而非基于已知信息的推测。
Everybody can make mistakes.
Now you try
— Look! The lights in the office are still on.
— It ________ be Mr. Li. He went to Beijing on business this morning.
can B. can’t C. must D. needn’t
— Why is Tom so popular in the international school
— Because he ________ speak three languages.
Can B. must C. should D. may
3.— ________ I use your phone to make a call
— Of course.
A. Must B. Should C. Do D. Can
May 的主要用法
表示没有把握的推测
表示请求
表示祝愿
may表示请求, 比can更有礼貌
May I come in
肯定回答 Yes , you can./ Sure. /Of course./ Yes, you may / Yes, please 否定回答
No, you cannot.= No, you can’t.
No, you mustn’t
(一般不用may not)
Sorry, I am afraid not.
表示推测，不确定，没把握的推测。
Where is he
He may be at home.
He may not be at home.（否定may 后面加not)
may 表示祝愿
它的基本句式是：May + 主语 + 动词原形 (+ 其他)
May all your dreams come true! (愿你梦想成真！)
May you be happy! (祝你快乐！)
无论主语是单数还是复数，后面的动词都必须用原形
最著名的例子莫过于《星球大战》中的那句台词：
"May the Force be with you!" (愿原力与你同在！)
改错练习题
原句： — May I open the window — No, you may not.
错误点： ____________________ 修改为： ____________________
原句： He is a very busy man. He may is at his office now.
错误点： ____________________ 修改为： ____________________
原句：May she has a wonderful time at the party!
错误点： ____________________ 修改为： ____________________
Now you try
No, you may not
No, you can’t/ you mustn’t/Sorry, I am afraid not.
He may is
He may be
May she has
May she have
Must 的主要用法
表示100%有把握的推测
或客观上的必然性
表示强制，义务
Must表示100%有把握的推测
He doesn't answer the phone. He must be sleeping.
他不接电话，肯定正在睡觉。
Must客观上的必然性
否定推测不用 must： 如果你想说“肯定不是/一定没……”，要用 我们刚刚讲过的can't。
例：It can't be him. (那肯定不是他。 不能说 It mustn't be him)
All living things must grow old and die. （所有生物都必然会衰老死亡。）
Must表示强制，义务
You must finish this job today.
你今天必须完成这项工作。
否定句：must not=mustn’t=千万不能，绝对禁止
You mustn't tell anyone about this. （你绝不能把这件事告诉任何人。）
疑问句：must 提前
Must I finish this job today
肯定回答：Yes, you must.
否定回答： No,you needn’t./No, you don’t have to.
否定回答不能用 No, you mustn‘t（那变成了“不，你严禁完成工作”）。
要表达“不必”，必须改用 needn't 或 don't have to。
Every morning, the sun ________ rise in the east. Nature has its own rules.
A. can B. must C. may D. needn’t
— Must I finish my homework right now — No, you ________. You can play football first.
A. mustn’t B. needn’t C. can’t D. shouldn’t
In this library, you ________ talk loudly.
A. needn’t B. don't have to C. mustn’t D. couldn't
Now you try
Have to 的用法
表示强制，义务
Have to表示强制，义务
Must 更强调 “主观义务”。
Have to 更强调 “客观要求”，受外部条件、规则或别人的要求而不得不做。
Must 和 have to 区别
I have to get up at 6:00 a.m. to catch the school bus.
（我不得不早上6点起床去赶校车。——这是校车时间定的，不是我自愿的。）
Have to 用法
Have to 是个情态动词短语，和can, may, must 不同。
因为它带有一个普通的动词 have，
所以它必须遵守普通动词的规矩——要随人称，数量和时态变化
I have to go home now.
She has to go home now.
They have to go home now.
have to 在否定句里，也像普通动词一样，要请出 don,t/doesn’t/ didn’t.
I have to go home now.
She has to go home now.
They have to go home now.
I don’t have to go home now.
主语 + don’t/doesn't/didn’t + have to + 动词原形
She doesn’t have to go home now.
They don’t have to go home now.
Musn’t (绝对禁止) VS don’t have to (没有必要)
You mustn't shout in the library.
(你禁止在图书馆大声叫嚷。——这是绝对禁止的)
You don't have to read every book here.
(你不必读完这里的每一本书。你可以读也可以不读。)
所以我们刚刚讲的must 疑问句：Must I finish this job today
肯定回答：Yes, you must.
否定回答：No,you needn’t./No, you don’t have to. （你不必今天完成）
不能用No, you mustn’t.(你禁止今天完成）
Have to 疑问句，一定要请出助动词（Do/Does）
Do /Does/Did+ 主语 + have to + 动词原形...
I have to go home now.
She has to go home now.
They have to go home now.
Do I have to go home now
Does She have to go home now
Do They have to go home now
Have to 的疑问句回答
回答非常简单，直接用 do/does/did来接：
问： Do you have to go 答： Yes, I do. / No, I don't.
问： Does he have to work 答： Yes, he does. / No, he doesn't.
Now you try
have to 专项练习题
My father is a doctor. He __________ work on weekends sometimes.
Tomorrow is Sunday. We __________ go to school.
__________ you __________ finish the work before you go home
has to
don’t have to
Do
have to
Should的主要用法
表示劝告，建议
Should 表示劝告，建议, 通常译为“必须，应该。”
陈述句
否定句
疑问句
You should go to bed now.
You should not (shouldn’t) go to bed now.
Should后面加not
Should 提前
Should I go to bed now
(回答：Yes, you should. /I think so. /That’s a good idea.
No, you shouldn’t. /I don’t think so. )
What should I do
Now you try
It is raining outside. You ________ take an umbrella with you when you go out.
A. should B. shouldn’t C. can’t D. may not
We ________ eat too much candy before sleep. It's bad for our teeth.
A. should B. shouldn’t C. must D. have to
need 和 dare（敢） 既可以作情态动词，也可以作行为动词。
情态动词用法 (这种用法在现代英语中很少见了）
后接动词原形，无第三人称单数变化。
He need come.
否定式直接加 not（needn’t/daren’t）。
He needn’t come.
疑问句直接提前，无需助动词。
Dare he come
行为动词用法 (常用用法）
后接 to do 不定式（need to do/dare to do），有第三人称单数变化（needs/dares）
He needs to come.
否定式需借助助动词+not
He doesn’t need to come.
疑问句需借助助动词
Does he dare to come
。
填空练习：My Busy Saturday
请从 can, may, must, have to, should 中选择最合适的词填空。
It is Saturday today. I don't (1)__________ go to school, but I am still busy. First,
I (2)__________ finish my homework.
I want to go out, so I ask my mother, “(3)__________ I go to the park with my friends ” She says, “Yes, you (4)__________ , but you (5)__________ come back before 5:00 p.m. It's too cold in the evening.”
I am happy because I (6)__________ play football very well, and I want to show my friends!
have to
must
May/Can
can
should
can
什么是祈使句？
简单来说，祈使句（Imperative Sentence）就是用来下命令、提要求、给建议或者发出禁止的句子。
祈使句通常是面对面说的，所以主语 You（你/你们）通常会被省略掉。很多情况下句子直接以动词原形开头
祈使句特点
祈使句三大句型
1，肯定式：动词原形 + 其他
直接告诉对方要做什么。
Listen to me! 听我说！
Be quiet! 保持安静！
(注：如果是形容词，前面要加 Be, be 是 am, is, are的动词原形)
2，否定式：Don‘t + 动词原形+其他
告诉对方不要做什么。
Don't talk! 不要说话！
Don't be late! 别迟到！
可以在句子最前面或最后面加上please,更加有礼貌。
Please listen to me!
Listen to me, please!
3，Let 建议式
Let+sb(通常为第一或第三人称宾格)+ do sth (动词原形)
建议大家不要做某事时，否定在 Let's 后面加 not。
Let's not go home.
Let’s not play football here.
让某人做某事
let 后面跟的是其他人
（比如 let him, let her, let the boy）
Let him go out.
Let the boy have the book.
不让某人做某事
否定句通常在最前面加 Don’t。
Don't + let + 某人 + 动词原形
Don’t let him go out.
Don’t let the boy have the book
建议大家做某事
Let's go home.
Let's play football here.
祈使句的回答
肯定回答可以用will
也可根据具体情况回答
OK / All right. (好)
Sure / Of course. (当然可以。)
No problem. (没问题。)
I'll do it right away. (我马上就去做。)
Yes, sir/madam. (是的，先生/女士)
否定回答可以用won’t
也可根据具体情况回答
Sorry, I can't. I'm busy. (抱歉，我不能。我很忙。)
I'm afraid I can't. (恐怕我不能。)
No, let‘s not. (不，我们还是别这样了 。)
祈使句类型 肯定回答 (同意) 否定回答 (拒绝)
Open the door. OK. / All right./Yes, I will. Sorry, I won’t. /Sorry, I'm busy.
Let's play football. Good idea! No, let's not.
辨析练习：下列哪些是祈使句？
（请在祈使句后面的括号内打“√”）
Open the window, please. ( )
He is cleaning the classroom. ( )
Don't be late for school again. ( )
studying hard is very important. ( )
Let's have a rest under the tree. ( )
Now you try
下列每个句子都有一个错误，请找出来并改正。
Coming in and close the door, please. 错误：__________ 改为：__________
No talk in the library. 错误：__________ 改为：__________
Doesn't play football in the street. 错误：__________ 改为：__________
Careful, please! The floor is wet. 错误：__________ 改为：__________
Let's don't go to the park this weekend. 错误：__________ 改为：__________
Coming
come
No talk
Don’t talk
Doesn’t
Don’t
Careful
Be careful
Let’s don’t
Let’s not
Thank you!

展开更多......

收起↑