现在完成时课件.ppt

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

Have/has+ S (主语)+PP(过去分词)?
Yes, S+have/has.
No, S+have/hasn’t.
(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?
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
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
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-e
e became e  run ran run