文档介绍：抽屉原理
黑河四小:王红梅
把4个苹果放进3个抽屉里,可以怎样放?
例1
1、先独立思考。
2、把自己的想法和组内同学交流。
3、如果需要动手操作,要分工明确并全面
考虑问题。
一.           情态动词的使用:can, must, may, might, need,
(能够), must(必须), may(可以)
结构:主语+can/must/may+动词原型
He can make the tea.
Sally can air the room.
We can speak English.
★变疑问句将情态动词移到句首
Can he make the tea?
Can Sally air the room?
Can we speak English?
★变否定句在情态动词后面加not
He cannot make the tea.
Sally cannot air the room.
We cannot speak English.
★肯定回答及否定回答
Yes, he can. No, he cannot.
Yes, she can. No, she cannot.
Yes, we can. No, we cannot.
★特殊疑问句:
What can you do?
(必背)
注意:情态动词的句子没有第三人称单数的变化,不要在情态动词或动词后面加S。
to的区别
must 表示必须,是主观上觉得应该做,have to是不得不,是由于客观条件逼迫的必要要做
must 只能用在表示现在和将来的句子里,而have to do可以用在任何时态
, may, might表示猜测:
must do 表示对现在事实的猜测
must have done表示对过去事实的猜测
must have been doing 表示对过去正在进行的事实的猜测
may/might do, may/might have done表示没有任何事实依据的猜测,might的可能性更小。
can’t/couldn’t 表示不可能
用法:
表示“需要”时为实意动词,后面可以加名词,也可以加不定式:
I need a pen. Do you need any beer? No, I don’t.
I need to have a rest.
Need doing=need to be done,表示被动
The flowers need watering.
Need在否定时做情态动词使用
You needn’t go so early. =You don’t need to go so early.
Must I clean the desk right now? No, you needn’t.
一.           不定代词及不定副词:
I looked for my book everywhere, but I can’t find it anywhere.
If you want go somewhere, if you want to be someone, you must wake up.
Help! Somebody? Anybody?
You are really something.
Since everybody is here, let’s begin our class.
Where did you go? I went nowhere.
Nobody is at home.
I have nothing left.
:
What +名词+主语+谓语
What a beautiful girl she is!
How + 形容词+主语+谓语
How beautiful the girl is!
三.           祈使句:
第二人称:
let+其他人称代词
祈使句的否定,加don’t
反意疑问
祈使句(第二人称)
★肯定句动词原型
例, Come here, please. Go downstairs, please. Stand up. Sit down. Be quiet. Be careful.
祈使句中如果有唤语,一定要用逗号隔开,放在句首或者句尾
Come in, Amy.
Sit down here, Tom.
Mary, give me a book please.
★否定:Don't+动词原型
Don'e here.
Don’t sit down.
Don’t stand up