文档介绍：Grammar and usage
Form: have/has + done
Present Perfect Tense
Part A
1我们用现在完成时来讲发生在过去的动作,但是对现在有影响。
They have cleaned the classroom. (They cleaned the classroom and the classroom is clean now.)
I have finished my homework. (I finished my homework and I am free now)
The boy is very happy.
The boy ___________ (catch) a bird.
(Connection with the past: The boy caught a bird. Connection with the present: The boy is happy. )
has caught
Look, the window is open. Eric opened the window just now.
Eric ___________________(already open) the window.
(Connection with the past: Eric opened the window.
Connection with the present: The window is open.)
has already opened
The boys are tired. They _____________ (just play) a ball game.
(Connection with the past: The boys played a ball game.
Connection with the present: The boys are tired.)
have just played
2 现在完成时还可以表示动作发生在过去一直延续到现在。常与一段时间连用
________________________________
past now future
came has lived
He hasn’t given me any more trouble since then.
We have discussed the topic for 3 days
They have made rapid progress during/in the past few years