人教版八年级英语上册 Unit 9 Can you come to my party语法情态动词课件（共有PPT17张）

(共17张PPT)
Unit 9
每日一句——中考常用谚语积累
All things are difficult before they are easy.
万事开头难。
情态动词
情态动词是表示主语情感态度的动词，必须和动词原形一起使用构成谓语。
具有情态动词特征的词组：
have to 必须
used to 过去常常…
ought to 应该
had better 最好…
原形 过去式
can
may
will
shall
dare
need
must
could
might
would
should
dared
= should
+V原形
意义(辨析)
情态动词 can / could
① 表能力
I can play the piano.
I could play the piano when I was 12.
② 表请求/邀请
—Can you come to my party
—Could you come to my party
—Yes, I can. / No, I can’t.
③ 表推测
The red hat can’t be his, because his is green.
He won’t do this. It could be wrong.
can→现在的能力
could→过去的能力
can→语气生硬
could→语气委婉礼貌
could→不确定推测
注意：回答用can，不再委婉！
can’t→否定推测
表能力
表请求/邀请
表推测
can：现在的能力
could：过去的能力
can：语气生硬
could：语气委婉礼貌
回答用can
can’t：否定推测
could：不确定推测
情态动词 may / might
① may表请求
May I sit here
回答： Yes, you can.
No, you can’t.
② 表推测
That may/might be Mr. Green, I am not sure.
may→语气较委婉礼貌
注意：回答用can，不再委婉！
may/might→不确定推测
may表请求
语气委婉礼貌
回答用can
表推测
may / might：不确定推测
情态动词 will / would
① 表将来
I will go to see a movie with him tomorrow.
I wouldn’t go to see a movie with him last time.
② 表请求/建议
Will you go to see a movie with me
Would you go to see a movie with me
will→一般将来时
would→过去将来时
will→语气生硬
would→语气委婉礼貌
表将来
表请求/建议
will：一般将来时
would：过去将来时
will：语气生硬
would：语气委婉礼貌
情态动词 shall / should
① should表责任义务(应该)
You should finish your homework before hanging out.
② shall表征求意见(好不好)
Shall we go home now
Shall they start
shall表建议：好不好
should表责任义务：应该
情态动词 must
① 肯定形式must：
表必须
You must go home right now.
—Must I go home right now
—No, you needn’t/don’t have to
表肯定推测
The green hat must belong to Mr. Green, I am sure.
② 否定形式mustn’t：表禁止不准
You mustn’t go out without my permission(允许).
= can’t
肯定形式must
否定形式mustn’t
表必须
表肯定推测
表禁止不准 = can’t
提问时否定回答
needn’t
don’t have to
need
① 实意动词(肯定句)
need to do sth
I need to go now.
② 情态动词(否定句/疑问句)
—Must I do it
—No, you needn’t.
实意动词
情态动词
肯定句
否定/疑问句
need to do sth
+V原形
意义(辨析)
表推测
情态动词表推测
肯定：must 肯定…
否定：can’t 不可能…
不定：might/may/could 可能…
He must be home because the light is on.
That can’t be him because he went to Paris.
He might/may/could be Tom. I am not sure.
+V原形
意义(辨析)
表推测
肯定：must
否定：can’t
不确定：may / might / could
must 提问时的否定回答
don’t/doesn’t have to
needn’t
See you!