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(共28张PPT)
Modals (2)
UNIT 2
Let’s celebrate!
Review
Modals Meanings Functions
be able to
dare
have to
had better
need
Ability
Courage
Strong advice
Advice
Necessity/advice
be afraid to do something
have the ability to do something
give advice to do something
be necessary to do something
give strong advice to do something
Can/Could
Must
May
Might
Modals
Meanings
Functions
Have to do something
Expressing a wish or hope/
Be possible to do something .
Give advice /Indicate less possibility
Be able to do sth / Indicate possibility
1) What do the words in red indicate: an order, a request, ability or possibility
The words in red indicate possibility.
a That is why Letters from Father Christmas could be the perfect book…
b The children must have been very excited as they opened it.
c … they might/may not receive their presents if they were not good.
1. Look at the sentences from the reading passage and answer the questions.
Can/Could
Must
May
Might
Modals
Meanings
Functions
Have to do something…
Expressing a wish or hope/
Be possible to do something …
Give advice /Indicate lower possibility…
Be able to do sth / Indicate possibility…
indicate possibility
2) Will the meaning of sentence (a) change if we replace (替换) “could” with “must” or “might”
If we replace “could” with “must”, the meaning of sentence (a) will change. It means the speaker is quite sure about the statement （声明）. If we replace “could” with “might”, the meaning of sentence (a) will remain more or less the same. “Could” and “might” in affirmative sentences (肯定句) have a similar meaning when indicating possibility.
1. That is why Letters from Father Christmas could be / must be / might be the perfect book...
那就是为什么《圣诞老人的来信》可能 / 一定 / 或许是一本完美之书……
情态动词 + 动词原形，表示对现在的推测
3) What happens if we change “must” and “might” in sentences (b) and (c) into “could”
If we change “must” in sentence (b) into “could”, it means the speaker is not sure about the statement, and it’s only a possibility.
2. The children must have been / could have been / might have been very excited as they opened it.
孩子们打开它的时候一定 / 可能 / 或许很兴奋。
must have been: quite sure about the statement
could have been: not very sure about the statement
might have been : not sure about the statement
情态动词 + 完成式，表示对已发生情况的推测
3) What happens if we change “must” and “might” in sentences (b) and (c) into “could”
If we change “might” in sentence (c) into “could”, it means it’s impossible for the children to receive presents.
3. ... they might / could / must not receive their presents if they were not good.
如果他们表现不好，他们可能收不到 / 就收不到 / 绝不能收到礼物。
might not: indicate possibility
could not: indicate impossibility
must not: they are not allowed to receive the presents
各情态动词语气从弱到强依次为：
Might -may - could -can -must
Grammar: Modals (2)
情态动词
(modals)
没有人称、数的变化
必须和其他动词一起构成谓语
用来表示态度、愿望、推测
情态动词表推测的用法：
1) can+动词原形
A.用于肯定句,表示客观可能性,意为“可能”,即从理论上看是可能的,但不一定会发生。例如:
As a human being, anyone can make a mistake.
作为人类,任何人都有可能犯错。
B.用于否定句或疑问句,表示对现在的动作或状态进行主观的猜测,意为“可能”,或表示惊异、怀疑等态度。例如:
a. He can't have a lot of money. 他不可能有很多钱。
b Can it be that it was I, not he, who was mistaken
难道是我弄错了,而不是他弄错了
情态动词+动词原形:现在或将来的情况进行推测。
情态动词表推测的用法：
情态动词+动词原形:现在或将来的情况进行推测。
2) may+动词原形,表示主观的推测,意为“或许”,用于肯定句和否定句均可。例如:
a. He may be very busy now. 他现在可能很忙。
b. He may not be at home. 他可能不在家。
注意:表示可能性时,can't语气较强,表示“不可能”; may not语气较弱;表示“可能不,或许不”。
情态动词表推测的用法：
情态动词+动词原形:现在或将来的情况进行推测。
3) might+动词原形,表示推测,意为“可能",可以指过去的情况,也可以指现在的情况,但语气比may更加不肯定。用于肯定句或否定句均可。例如:
a. They might have a lot of work to do now but I'm not sure.
他们现在可能有很多活儿要干,不过我不确定。
b. She was afraid they might not like the idea.
她担心他们可能不喜欢这个想法。
情态动词表推测的用法：
情态动词+动词原形:现在或将来的情况进行推测。
4) could+动词原形,意为“可能”,可以指过去的情况,也可以指现在的情况,语气缓和。多用于否定句或疑问句。
例如：
He looks young. He couldn't be over 50.
他看起来很年轻,不可能超过50岁。
b. Could it be true
那可能是真的吗
情态动词表推测的用法：
情态动词+动词原形:现在或将来的情况进行推测。
5) must+动词原形,表示猜测,意为“准是,一定”,通常用于肯定句。
例如：
a. This must be your room. 这一定是你的房间。
b. Look at his new car. He must have a lot of money.
瞧他那辆新车。他肯定很有钱
【注意】mustn’t 不许可，不应该，不表示推测。
c. You mustn't smoke here.（这里禁止吸烟。）
情态动词表推测的用法：
情态动词+完成式（have done）:过去已发生的情况进行推测。
must+完成式,一定，想必，语气较强。表示对已发生情况的推测,通常用于肯定句。
例如: She must have gone home. 她肯定已经回家了。
情态动词表推测的用法：
情态动词+完成式（have done）:过去已发生的情况进行推测。
2) can+完成式,表示对已发生情况的推测,主要用于否定句或疑问句。
例如：
a. You can't have forgotten her. 你不可能已经忘记她了。
b. Where can she have put it 她到底把它放在哪儿了呢
情态动词表推测的用法：
情态动词+完成式（have done）:过去已发生的情况进行推测。
3) could+完成式,表示对过去情况的推测,多用于否定句或疑问句。
例如：
a. He could not have been more than 16 at that time. 他当时不可能超过16岁。
b Could she have forgotten my address 她会忘记我的地址吗
情态动词表推测的用法：
情态动词+完成式（have done）:过去已发生的情况进行推测。
4)may/ might+完成式,表示对已发生事情的不肯定的推测,might相比may语气更加不肯定。
例如：
He may / might have come by train. 他可能是坐火车来的。
情态动词must, can/could, may/might 均可表示推测, 它们可以对过去、现在或将来的情况作出语气强弱不同的推测。
1. 表示肯定的推测时：
各情态动词语气从弱到强依次为: might → may → could → can → must；
2. 表示否定的推测时：
can’t / couldn’t 不可能，语气较强；
may not / might not 可能不，语气较弱。
Summary
3. 情态动词表示推测时, 在用法上有一些限制:
① must只用于肯定句中，意为“一定，准是”。如:
This must be your room.
② can/could多用于否定句和疑问句中。如：
He looks young. He couldn’t be over 50.
③ may / might用于肯定句和否定句中。如：
They may not know his address.
She told me that she might go to Hawaii this winter.
【注意】mustn’t 不许可，不应该，不表示推测。
情态动词 对现在和未来的推测 对过去的推测 使用句型
Must Must+动词原形 Must have done 肯定句
May/might May/might+动词原形 May/might have done 肯定句，否定句
Can/could Can/could+动词原形 Can/could have done 否定句，疑问句（could可用于肯定句）
should 用来表示一种估计的情况“按理会+估计会” should + do/be Should have done 肯定句，否定句，疑问句
表推测时，must, may, might, may not和can't这五个表达的语气依次递减： must：一定（语气肯定） may：也许（不很肯定） might：或许（比may语气更弱） may not：也许不（表否定） can't：一定不（must的反义）
Summary
You must be tired now!
It may/might/could be him.
be Lucy.
That must
may / might / could be from our school.
They
that can’t be Lucy.
Exercise
Black Friday is one of the busiest shopping days of the year. Stores have big sales and open their doors very early.
Exercise
The man with a wallet in his hand might be a bit unwilling to pay.
Exercise
The woman in red must be very excited to buy so many things.
Exercise
The woman with glasses may be very tired to get up so early and carry so many bags.
Exercise
The cashier might be feeling uncomfortable as he is sweating a lot.
Exercise

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