人教新目标(Go for it)版七年级下Unit 4 Don't eat in class. Section A(Grammar Focus－3c) 课件（25张PPT）

(共25张PPT)
Unit 4　Don't eat in class.
第三课时　Section A (Grammar Focus－3c)
情景导入
Please take out a piece of paper and write down some school rules.Then make some new school rules or class rules. Then let's discuss your school rules，which is good，and which we should change？
We can't run in the hallway.
What are the rules in our school
We have to wear uniforms to school.
And what eles
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.
Grammar
Focus
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
祈使句一般用来表示请求、命令、劝说、号召、警告等。在祈使句中，通常省略主语you，其肯定形式以动词原形开头，否定形式是在动词原形前加don’t。祈使句句尾用句号或感叹号，读时用降调。为表示礼貌，可以在句首或句尾加上please。句末用please时，前面通常加逗号。
祈使句
肯定句：动词原形 (+宾语)+其他.
否定句：Don’t+动词原形 (+宾语) +其他.
Wear the school uniform on weekdays, please.
上学日请穿校服。
Don’t watch TV before dinner. 晚饭前不要看电视。
Do 型祈使句的构成
肯定句：Be+表语+其他.
否定句：Don’t+be+表语 +其他.
Be careful next time.下次要细心。
Don’t be late for school! 上学不要迟到!
Be 型祈使句的构成
肯定句：Let+宾语+动词原形+其他.
否定句：Don’t+let+宾语+动词原形+其他.
或Let+宾语+not+动词原形+其他.
Let’s have a rest. 咱们休息一下吧。
Don’t let him go swimming. = Let him not go swimming.
不要让他去游泳。
Let 型祈使句的构成
(1) No+v-ing! / No+名词!
No fishing! 禁止钓鱼!
No parking! 禁止停车!
No photos! 禁止拍照!
(2) never 代替don’t 来加强语气。
Never give up! 决不放弃!
其他类型的否定祈使句
情态动词have to与must
共同点
二者均可表示“必须”，其后均接动词原形。
It’s too late. I have to take a taxi. 太晚了，我必须乘出租车。
I must go now. 我必须现在就走。
不同点
have to 强调因客观因素影响而不得不做某事，跟主观意愿无关，通常上下文中会有暗示客观因素的句子，多译为“不得不”。
可用于不同的时态，有人称和数的变化，其一般现在时的第三人称单数形式为has to；过去式为had to。
have to的否定形式为don’t/doesn’t /didn’t have to，表示“不必”。
must 表示因主观需要或责任感的驱使而有必要或义务去做某事，多译为“必须”。
一般只用来表示现在，没有人称和数的变化。
must的否定形式为mustn’t，表示“禁止，不准”。
3a
Write the rules for the school library.
Library Rules
1. ______________________________
2. ______________________________
3. ______________________________
4. ______________________________
Don’t talk.
1
2
3
4
Don’t eat in the library.
Don’t listen to music in the library.
Don’t take photos in the library.
3b
Use the words to make questions about the rules. Then write answers according to your school.
Q:____________________________________(she/have to/in
the library)
A: ____________________________________.
Be quiet
Does she have to be quiet in the library
Yes, she does
Eat
Q:___________________________________ (he/have to/in
the dining hall)
A:___________________________________
Does he have to eat in the dinning hall
Yes, he does.
Q:___________________________________(we/can/in the
hallways)
A:___________________________________
Listen to music
Can we listen to music in the hallways
No, we can’t.
Wear a hat
Q:___________________________________(we/can/in the
classroom)
A:___________________________________
Can we wear a hat in the classroom
No, we can’t.
3c
Make up five cool rules for your dream school. Share your rules with the class. Your classmates vote for the Coolest School!
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 …
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.
For example
问题探究
▲must和have to的用法
(1)你不得不穿校服吗？
Do you have to wear the school uniform
(2)——我现在必须要走吗？ —Must I go now
——不，你不必。 —No，you needn't.
2. Can we bring music players to school？
我们可以把音乐唱片机带到学校吗？
课堂小结
Section A (Grammar Focus－3c)
随堂练习
Ⅰ.根据句意，用方框中所给词组的适当形式填空。
1. You should ____________．The baby is sleeping.
2. She likes __________________ on school days.
3. We can't listen to music __________．
in class，on time，have to，wear a uniform，be quiet
be quiet
wearing a uniform
in class
4. —Can I finish my homework tomorrow
—I am afraid not.You ________ hand it in today.
5. You can't arrive late for class.You must be _________．
in class，on time，have to，wear a uniform，be quiet
have to
on time
1. David, _______ make trouble at school.
A.can’t B. don’t C. doesn’t D.didn't
2. —Mom, can I play computer games this evening
—_______ your homework first, and then we’ll talk about it.
A. Finishing B. Finish C. To finish D. Finished
3. Buses _______ stop when the traffic lights turn red.
A. can B. may C. must D. might
B
B
C
Ⅱ.单项选择。
4. We should keep quiet in the library. We _____ speak loudly
（大声地）.
must B. mustn’t C. can D. needn’t
5. I _____ go now, or I’ll miss my train.
A. can B. might C. must D. could
6. He _____ stay at home, because it’s raining outside.
A. have to B. has to C. must D. can’t
B
C
B