现在完成时课件.ppt

文档介绍：现在完成时
The Present Perfect Tense
现在完成时课件
一、构成:
have/has+动词过去分词
现在完成时课件
二、含义:
(定义一), yet, ever, never, just, before等.
现在完成时课件
句式构成
:
S(主语）+have/has(助动词）+PP(过去分词)+(其他）。
现在完成时课件
2. 否定句:
S ( 语)+have/has+not +PP(过去分词)+(其他）。
现在完成时课件

Have/has+ S (主语)+PP(过去分词)?
Yes, S+have/has.
No, S+have/hasn’t.
现在完成时课件
（改为否定句和一般疑问句并肯否回答) I have seen him since his wedding day.
→I haven’t seen him since his wedding day .
→Have you seen him since his wedding day?
现在完成时课件
He has written to me since I have been ill.(改为一般疑问句)
→ Has he written to you since you have been ill?
→ He hasn’t written to me since I have been ill
现在完成时课件
不规则动词原型-过去式-过去分词形式：
1） AAA型(三种都一样)
如：cost cost cost cut cut cut  hurt hurt hurt shut shut shut  set set set
2）ABB型(过去式与过去分词相同)
如: bring-brought-brought  catch caught caught  lead led led
现在完成时课件
3） ABC型(三种都不一样)
如：begin-began-begun
grow grew grown ring rang rung  break broke broken
4）ABA型(原形与过去分词相同)
如: come-came-come
become became become  run ran run
现在完成时课件