现在完成时课件.ppt

**Present Perfect Tense
现在完成时
(has)+过去分词构成
.
.
4..动词的过去分词:规则变化(和过去时一样)
visit-visited-visited leave-left-left
graduate-graduated-graduated
不规则变化(如下)
不规则变化:
am/is-was-been are-were-been
begin-began-begun 开始 do-did-done

give-gave-given 给 go-went-gone去
know-knew-known 知道 fly-flew-flown 飞

see-saw-seen看
speak-spoke-spoken说话
take-took-taken拿走
come-e来
1。表过去发生的某一动作对现在造成的影响或结果,例如
I have just cleaned my clothes. 我刚洗过衣服。
(“洗衣服”是发生在过去的动作,对现在造成的结果是“衣服干净了”)
I have just had my breakfast.
通常与表示包括现在在内的时间副词 just(刚刚), already(已经), before, yet(一般疑问表示已经;否定句表示还) never(从不), ever(曾经)等状语连用
① I have never heard of that before.
② Have you ever ridden a horse?
③ She has already finished the work.
④ Have you milked the cow yet? Yes, I have done
that already.
⑤ I’ve just finished my homework.
⑥ He has e yet.
对现在的影响:不饿
2。表示过去已经开始,持续到现在的动作或状态,也可以表示实质可能继续下去的动作或状态。通常和 for(一段时间), since(自从) 引导的时间状语连用.
I have been here for just over two years.
我到这儿已经两年了。
He has worked here since 1989.
从1989年,他就已经在这工作了
注意点一:
现在完成时与一般过去时的用法比较
一般过去时表示动作发生的时间在过去。试比较:
说明现在的情况:飞机在这儿
The plane has arrived . 飞机已经来了。
The plane arrived a quarter ago.
飞机是一刻中以前来的。(强调动作发生的时间在过去)
I have taught here for fifteen years.
我在这儿已经教了十五年。(表示十五年前的动作一直延续到现在,还可能会继续。)
I taught here for a year.
我过去在这儿教过一年。(表示“我“现在已经不在这儿任教了)
Homework:
A
B
C
Put the following sentences into English.
A: 火车已经开走了.
B: 什么时候开走的?
A: 半个小时之前开走的.
A: 这本书我已经买了两年了.
B: 你在哪儿买的?
A: 在我老家买的.
A: The train has left.
B: When did it leave?
A: It left half an hour ago.
A: I`ve had the book for two years.
B: Where did you buy it?
A: I bought it in my hometown.
注意点二、非延续性动词与现在完成时
短暂性动词在肯定句、疑问句中不能与时间段连用,这些动词是:e, begin, buy, borrow, arrive, come, die, fall, finish, get to know, go, join, leave, marry等。为了表述这种意思,我们常用相应的延续性动词have,keep等来代替非延续性动词。
他入党五年了。He joined the Party five years ago .
——He has been in the Party for five years.
——He has been a Party member for five years.
——it i