Section A
Grammar-3c
Practice
Can we …?
Yes, we can.
No, we can’t.
eat in class
listen to music outside
wear hats in school
fight in class
speak loudly in the
library
Don’t run in the hallways. Don’t fight.
What are the rules? We must be on time for
class.
Can we eat in the classroom?No, we can’t, but we can eat
in the dining hall.
Can we wear a hat in class? Yes,we can. / No,we can’t.
Does he have to wear a
uniform at school?
Yes, he does. / No, he
doesn’t.
What do you have to do? We have to be quiet in the
library.
Grammar Focus
1. 不要在楼道里跑。
______________________________
2. 不要打架。
____________________
3. 有什么规则？
______________________________
4. 我们必须按时上课.
_______________________________
阅读Grammar Focus部分，完成下列句子。
Don’t fight.
Don’t run in the hallways.
What are the rules?
We must be on time for class.
5. 我们可以在教室里吃东西吗？
_____________________________
6. 不能。但我们可以在餐厅里吃东西。
________________________________
________________________________
7. 我们可以在上课的时候带帽子吗？
_____________________________Can we wear a hat in class?
No, we can’t, but we can eat in the
dining hall.
Can we eat in the classroom?
8. 他在学校里必须穿校服吗？
__________________________________
9. 是的，必须。/ 不，不必。
_______________________________
10. 你们必须做什么？
_______________________________
11. 在图书馆里我们必须保持安静。
_________________________________
Yes, he does. / No, he doesn’t.
Does he have to wear a uniform at school?
What do you have to do?
We have to be quiet in the library.
情态动词can, must, have
to 后面都接动词原形
Think:
1. 情态动词在用法上有什么共同点？
2. can在本单元主要表示什么含义？它还可表达什么意思？
3. have to在用法上与其他情态动词有何区别？
Observe and learn.
一、祈使句
1. 用法：一般以动词原形开头，表示请
求、命令、劝说、警告等。在祈使句
中，通常省略句子主语第二人称you。
2. 句子结构
(1) 肯定句：__________+ 其他
在餐厅里吃东西。
________________________________
Eat in the dining hall.
动词原形
(2) 否定句: _____ + _________+ 其他
不要和同学们打架。
_______________________________
Don’t fight with your classmates.
Don’t 动词原形
(⑶) 以let引起的句子 ____+ sb.+V原形
让我们步行去上学吧。
_________________
(4) No + n/V-ing形式。表示“禁止...”
禁止停车！No Parking.
禁止吸烟！No Smoking.
Let
Let’s walk to school.
祈使句是用来表示请求、命令、劝说、
号召、警告等。祈使句中, 通常省略第二
人称主语you。句子中通常不出现主语，
谓语动词一律用原形。根据句子语气的
强弱，句末用感叹号或句号。
一、祈使句的肯定式
1. 以行为动词原形开头，简称Do型。
e.g. Come here. 到这儿来。
2. 以动词be开头，简称Be型e.g. Be quiet, please. 请安静。
3. 以Let开头，简称Let型。e.g. Let’s go! 咱们走吧!
注意
有时可在祈使句的句首或句尾加上please，使语气显
得客气、有礼貌。如果在句尾加please，应该用逗号
与前句隔开。
e.g. Go this way, please. 请这边走。
二、祈使句的否定式
1. Do型和Be型的否定式是在句首加don’t。
e.g. Don’t sit here. 不要坐在这儿。
Don’t be late. 别迟到。
2. 以let开头的祈使句，其否定式有两种：
一种是直接在句首加don’t，另一种是
“let + 宾语 + not +动词原形+ (其他)”。
e.g. Don’t let him go. 不要让他走。
Let’s not go there. 咱们别去那儿。
注意
“No+名词/动词⁃ ing形式”表示禁止或规
劝，常用于公共场所。
e.g. No photos! 禁止拍照！
No smoking！ 禁止吸烟！
must 必须；一定
表示主观需要或责任感的驱使有必要或有义务去做某事，没有
人称和时态的变化，后接动词原形。
句型结构：主语+must+动词原形+其他
e.g. You must come in time.
你必须按时来。
The children must be back before 6 o’clock.
孩子们必须6点前回来。
have to 必须；不得不
表示因客观的需要不得不做某事，有人称和时态的变化，后
接动词原形。
其否定式don’t / doesn’t have to表示“不必；没必要”。
否定形式和疑问句形式均需要借助助动词do才可以进行变化。
We _______wear a uniform every day.
Yes,____.
Look and say.
Do you have to wear a
uniform every day?
have to
No,______.
I do
I don’t
用have to
What do you have to do ?
I _______do homework
every day.
have to
I ______________________
on weekends.
have to clean my bedroom
What do you have to do ?
祈使句一般用来表示请求、命令、劝说、号召、警告等。
祈使句中, 通常省略第二人称主语you。
肯定式以动词原形开头，否定式一般在动词原形前加don’t。
e.g. Come and join us.
Read after me.
Don’t be late.
Don’t talk in class！
Don’t let the children swim in the river.
标志
Do you know the rules for the school
library?
Don’t eat in the library.
Don’t sing in the library.
Do you know the rules for the school
library?
Don’t take photos in the library.
Do you know the rules for the school
library?
No photos!
Don’t talk in the library!
in the library
No talking!
Be quiet !
Don’t listen to music in the
classroom!
in the classroom
Don’t smoke!
No smoking!
2021-6-7 27
in public (在公共场所)
Don’t talk loudly in public!
in public (在公共场所)
loudly
adv. 大声地
Library Rules
1. Don’t talk.
2. __________________
3. __________________
4. __________________
3a Write the rules for the school library.
Don’t listen to music.
Don’t eat or drink.
Don’t take photos.
方法指导：
1. 由图示可知都是一些禁止类的祈使句。
2. 可知应用“Don’t + 动词原形”句子。
1. Be quiet? (she/have to /in the
library)
Q: Does she have to be quiet in the
library?
A: Yes, she does.
3b Use the words to make questions
about the rules. Then write
answers according to your school.
1. 根据例句，可知要求我们造一般疑问句
并根据实际情况进行回答。
2. 先确定句子的主语。
3. 再确定用情态动词还是用助动词来构成
疑问语序。
4. 根据实际情况做出肯定或否定回答，答
语的主语要与问句保持一致。
2. Eat? (he/have to/in the dining hall)
Q: ________________________________?
A: _____________
3. Listen to music? (we/can/in the hallways)
Q: ________________________________?
A: _____________
4. Wear a hat? (we/can/in the classroom)
Q: _____________________________?
A: ____________
Then answer the questions.
Yes, he does.
Does he have to eat in the dining hall
Can we listen to music in the hallways
No, we can’t.
Can we wear a hat in the classroom
No, we can’t.
1. We can eat in class.
2. We don’t have to come
to school every day.
3. …
At my dream school,
we don’t have to
come to school every
day. We …
4. Make our school rules
At my dream school, we don’t
have to come to school every day.
We can eat in the classroom.
We can listen to music in class.
We don’t have to do homework.
We don’t have to wear school
uniforms at school.
Great! Jim’s school is the coolest.
Discuss and make rules for
the computer room in your
school.
Computer Rules
1. _______________
2. _______________
3. _______________
4. ________________
5. ________________
Computer Rules
1. ___________________________________
2. ___________________________________
3. ___________________________________
4. ___________________________________
5. ___________________________________
We must be quiet in the computer room.
Don’t eat or drink in the computer room.
Don’t run in the computer room.
Wear slippers in the computer room.
Clean the computer room every day.
根据短文内容，用括号内所给词的适当形式填空，使
短文完整、通顺。
Dear Mary,
Now I’m at Bill’s home. Please (1)________(help) me
do some things. First, (2)________(get) some food for
my dog Robot. After Robot finishes eating his food, you
can (3)________(clean) his small room. Then,
(4)________(take) him for a walk. (5)__________(not
let) him be with Mom’s dog Frank. They will fight.
Many thanks.
Your sister
help
get
clean
take Don’t let
用所给单词的适当形式填空。
1. Don’t ________(listen) to music in the
library.
2. Do we have to ________(clean) the room
every day?
3. You can’t ________(wear) sunglasses in
the classroom.
4. Please ________(arrive) at school on
time (准时).
5. John is often late for _______ (class).class
listen
clean
wear
arrive
将下面的句子改为祈使句，每空一词。
1. You can come in.
______ ____, please.
2. I can help you.
_____ me ______ you.
3. You can’t eat in class.
_______ _____ in class.
4. You can’t be late for school.
______ ____ late for school.
5. You can’t take photos here.
____ photos here.
Come in
Let help
Don’t eat
Don’t be
No
Ⅴ. 用can和can’t填空
1. Mr Green ______ smoke here, because
there’s a sign on the wall. It says “No smoking.”
2. It’s very hot outside. You ______ wear a hat.
3. We ______ eat in the classroom, because
it’s impolite to teachers.
4. I ______ go to bed after 11:00 on school night.
5. The students ______ read books and magazines
in the library.
can’t
can
can
can
can’t
1. We _______ clean our classroom after school.
2. She _______ make her bed after getting up.
3. It’s late. Mr. Beckman _______ go to
work by car.
4. Emily and Peter join a music club.
They ________ practice guitar every day.
Ⅵ. 用have to或has to填空
1. 肯定祈使句的常见句型结构：
① Do型：动词原形+宾语+其他. 如：
Open the door, please.
② Be型：Be+表语. 如：Be quiet!
③ Let型：Let+宾语+动词原形+其他.
(或：Let’s+动词原形+其他.) 如：
Let me help you.
又如：Let’s play tennis.
2. 否定祈使句的常见句型结构：
① Do型和Be型的否定式：Don’t+动词
原形 / be+其他. 如：Don’t forget me.
又如：Don’t be late.
② Let型的否定式：Don’t+let+宾语+动词
原形+其他. (或：Let’s+not+动词原形+其
他.) 如：Don’t let him go back. 又如：
Let’s not go swimming.
③ 警示语：No+名词 / 动词-ing形式. 如：
No talking.
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