文档介绍：Unit 5
Can e
to my party?
Grammar focus
Explanation
1. can 的用法
(1)表邀请。
若接受邀请,回答为:
OK./All right./Sure./ Of course./Certainly./
Yes(Sure),I’d love(like) to.
若不接受邀请,回答为:
Sorry,Ican’t.(+原因)
eg . Can e to the party?
Yes/Sure,I’d love/like to.
Sorry,Ican’t. I have to help my parents.
其他表邀请的句型:
1) Could /Will/Would e to the party?
2) Would you like /love e to the party?
3) I hope e to the party.
4) e to the party.
5) How/What ing to the party?
(2)表能力“能,会”否定句 can’t不能
eg. He can swim,but I can’t.
How long can you stay under water?
(3)在否定句,疑问句中表示“不可能”或“一定不”
eg. Can e ?No,he can’e.(他会来吗?不,他不能来.)
“have to”与其他的情态动词如:“can”, “may”“must”和“should”不同。
(1)这4个情态动词没有人称和数的变化,而have to有。它的第三人称单数为“has to”,过去时为had to, 如:
He should study hard .
他应该好好学习。
He has to study hard .
他不得不好好学习。
(2)这4个情态动词在一般疑问句中将它们放在句首, 在否定句中直接在他
们后边加not即可。
我们以can为例:
Can he go with us ?
他能和我们一起去吗?
He can’t go with us .
他不能和我们一起去。
而“have to”要加助动词do ,
has to要加助动词does ,还原 have to
had to要加助动词did,还原 have to
才可能完成其疑问、否定句。
试将下面三种话分别写成
(1)一般疑问句,并做肯定回答。
(2)否定句。
1: They have to go to the party .
Do they have to go to the party ?
Yes , they do .
They don’t have to go to the party.
2:He has to go to see the doctor .
Does he have to go to see the doctor?
Yes , he does .
He doesn’t have to go to see the
doctor .
3: She had to have a piano lesson yesterday.
Did she have to have a piano lesson
yesterday?
Yes, she did .
She didn’t have to have a piano
lesson yesterday.
2 .have to强调客观上需要做某事,即表示外界条件的需要不得不做某事,含有“客观所迫”的意味,它有人称和数的变化,可用于多种时态中,否定式为“不必”。
must强调说话者主观上认为必须做某事,含有“主观判断”的意味,它的否定式意为“禁止,不允许”。
eg. If one gets ill,he’ll have to see a doctor.
She has to go to school by bus.
We must go to school on time.
---Must I finish the homework now ?
---Yes, you must./No,you needn’t(don’t have to).
You mustn’t play football in the classroom.