初中英语情态动词讲解

初中英语情态动词讲解
Modal Verbs
Modal verbs are used to express the speaker's attitude towards an n or state.
Characteristics of Modal Verbs:
1.Modal verbs have a specific meaning.
2.Modal verbs cannot be used alone as the predicate。

They must be used with the base form of another verb to form the predicate.
3.Modal verbs do not change with person or number.
Structure and Meaning of Modal Verbs:
1.Basic sentence structure of modal verbs:
Affirmative sentence: subject + modal verb + base form of verb +。

Negative sentence: subject + modal verb + not + base form of verb +。

n sentence: modal verb + subject + base form of verb +。

2.Meanings of modal verbs:
must: necessary
can/could: ability
may/might: possibility
should: n
would: desire/willingness
have to: necessity
need: requirement
Basic Uses of Modal Verbs:
1.can (could for past tense)
Expresses ability or capability:
Two eyes can see more than one。

/ I can swim very well.
Expresses possibility:
He can't (couldn't) have enough money for a new car.
Expresses n:
Can I have a look at your new pen?
He asked whether he could take the book out of the reading-room.
Expresses n:
He can't (couldn't) be over sixty.
2.may (might for past tense)
Expresses n。

inquiry。

or possibility。

Might is used for past tense。

but can also be used for present tense in a more polite manner.
May (Might) I ask for a photo of your baby?
When answering a n with may。

it is acceptable to respond with may or with a positive response such as Yes。

please。

/ Certainly。

/ Sure。

/ Of course.
May表示可能，但程度不如can强烈。

例如，He may be at home.（他可能在家里。

）They might be having a meeting。

but I’m not sure.（他们有可能在开会，但我不确定。

）
必须的意思可以用must表示，用于肯定句和疑问句，但在否定句中表示禁止。

例如，We must do everything step by step.（我们必须一步一步地做。

）You must get home before 9:00.（你必须在9点之前回家。

）He must be ill。

He looks so pale.（他一定生病了。

他的脸色很苍白。

）在疑问句中，肯定回答用must，否定回答用needn’t或don’t have to。

Should表示责任或义务，用于各种人称。

例如，You should be polite to your teachers.（你应该对老师有礼貌。

）它也可以表示推测，例如The film should be very good as it is starring first-class actors.（这部电影应该很好，因为它由一流演员主演。

）
Will表示意愿，可以用于各种人称。

例如，I will do anything for you.（我愿意为你做任何事。

）在疑问句中，用于第二人称，表示询问对方的意愿或向对方提出请求。

例如Will you close the window?（请你把窗户关上好吗？）
Would是will的过去式，表示过去时间的意愿或意志。

例如，They would not let him in because he was poorly dressed.
（因为他衣着破旧，他们不让他进去。

）I said I would do anything for you.（我说过我愿意为你做任何事。

）
2) Would is used in present tense to express requests。

ns or ns in a polite way.
For example: Would you like another glass of beer?
Could you please pass me the salt?
7.Need
1) As a modal verb。

need is mainly used in negative and interrogative sentences。

As a main verb。

it can be used in affirmative。

negative and interrogative sentences.
For example: You needn't telephone him now.
Do I need to bring anything to the party?
2) When answering a n with need。

the affirmative answer is usually must and the negative answer is needn't.
For example:
Need I come。

--Yes。

you must.
Do I need to bring a gift。

--No。

you needn't.
Practice Exercises:
1."__________ I take it out?" "I'm sorry。

you __________."
A。

Could。

couldn't B。

Might。

might not C。

Could。

can D。

May。

can
Answer: A。

Could。

couldn't
2."Need we do this job now?" "Yes。

__________."
A。

you need B。

you should C。

you must D。

you can
Answer: C。

you must
3.__________ to have lunch with us today?
A。

Do you likes B。

Would you like C。

Will you liked D。

Have you liked
Answer: B。

Would you like
4.-Is John coming by train。

-He should。

but he __________ not。

He likes driving his car.
A。

must B。

can C。

need D。

may
Answer: D。

may
5.Peter __________ come with us tonight。

but he isn't very sure yet.
A。

must B。

can C。

may D。

will
Answer: C。

may
6.I thought you __________ be hungry。

so I have brought you some cakes.
A。

may B。

might C。

can D。

could
Answer: B。

might
7.We must hurry because there isn't much time left.
8.Amy must have worked hard last week to do well in the English test.
9.I'm afraid not。

but thanks。

I have drunk a lot of tea.
10.You mustn't smoke here。

Look。

there is a "NO SMOKING" sign here.
11.It can't be Helen。

She has gone to Beijing.
12.Drivers must。

and wait till the green light when the traffic lights turn red.
Revised:
7.We must hurry because time is running out.
8.Amy's hard work paid off as she did the best in the English test.
9."Thanks。

but I've had enough tea," I declined the offer for juice.
10."No。

you can't smoke here," I pointed at the "NO SMOKING" sign.
11."It can't be Helen," I said。

recalling that she has gone to Beijing.
12."Drivers must。

and wait for the green light when the traffic lights turn red," I explained.。