现在完成时和过去完成时

现在完成时(The Present Perfect Tense)

I.概念：过去发生或已经完成的动作对现在造成的影响或结果，或从过去已经开始，持续到现在的动作或状态。

II.时间状语：recently, lately, since…for…,in the past few years, etc.

过去分词的构成分规则的和不规则的，规则的与过去式的构成方法一样，不规则的只有单独记了。

III.不规则的过去分词也有规律可循,只能自己记，无人能帮你。

1 陈述句结构：肯定句: 主语＋have( has) +过去分词＋其它。

否定句: 主语＋have not / has not +过去分词＋其它。

2 一般疑问句结构：Have( Has )＋主语＋过去分词＋其它？

eg. He has already finished his homework.

He hasn’t finished his homework yet.

Has he finished his homework yet?

IV.常搭配的副词:already, yet, just, ever, never这几个词的位置除了yet常在句首或者句尾外，其余的通常都在句中，即have/has的后面，行为动词的前面。但already也可在肯定句尾，表示强调，在疑问句末尾表示惊讶等。

eg. Has he finished his homework already? 对他完成了作业感到惊讶。

另，before 也可以与现在完成时连用，ago只能与过去时连用。

eg. I’ve ever been there before. It was ten years ago.

V.常用用法

1、表示过去发生或者已经完成的动作对现在造成的影响或者结果。

eg. The doctor has left .(他现在不在这儿，找不到他了。)

The students have cleaned the classroom.(现在教室是干净的)

I have just read the book.( 现在我知道这本书的内容了)

比较：I read the book last month.(只是说明read这个动作是在上个月发生的而已，没有谈及对现在有什么影响)

VI总结：现在完成时与一般过去时的区别：现在完成时强调的是过去发生的动作对现在造成的影响或者结果，强调的是现在的情况或者状态，与过去没有关系，不能和表示过去的时间状语连用。而一般过去时只表示这动作是在过去某个时间发生的，或者说是过去某个时间发生了某个动作而已，和现在没有关系。它就可以和表示过去的时间状语连用，比如：yesterday, just now , last year , in 2000, some minutes ago, the day before yesterday etc.

eg. I have seen the film already. (现在我已经了解这部电影的内容了，至于什么时候看的没有关系，反正我已看过了。)

I saw the film last year .( 只是表示我是去年看的这部电影。)

2、表示某个动作或者某个状态从过去某一时间开始一直持续到现在(包括现在在内) 的动作（用行为动词表示）或状态（be动词表示）常与for（+时间段）,since （+时间点或过去时的句子）连用.

eg. Mary has been ill for three days.

I have lived here since 1998.

注意：（超重要）：瞬间动词（buy,die,join,lose……）不能直接与for since 连用。要改变动词

come-be go out-be out finish-be over open-be open die-be dead 1.have代替buy

My brother has had(不能用has bought) this bike for almost four years.

2、用keep或have代替borrow

I have kept(不能用have borrowed) the book for quite a few days.

3、用be替代become

How long has your sister been a teacher?

4、用have a cold代替catch a cold

Tom has had a cold since the day before yesterday.

5、用wear代替put on

a)用“be＋形容词”代终止性动词

1、be＋married代marry

2、be＋ill代fall (get) ill

3、be＋dead代die

4、be＋asleep代fall (get) asleep

5、be＋awake代wake/wake up

6、be＋gone代lose,die,sell,leave

7、be＋open代open 8、be closed代close/shut

9、be＋missing(gone,lost)代lose

b)用“be＋副词”代终止性动词

1“be＋on”代start,begin 2“be＋up”代get up

3“be＋back(to)”代return to,come back to,go back to

4“be here (there)”代come(arrive,reach,get) here或go (arrive,reach,get) there 等等

c)用“be＋介词短语”代终止性动词

1.“be in/at +地点”代替go to /come to

2.用be in the army 代替join the army

3.“be in/at +地点”代替move to

常用瞬间动词变延续性动词表：

1. have arrived at/in sw. got to/reached sw. come/gone/moved to sw.

→have been in sw./at…相应的介词

2. have come/gone back/returned →have been back

3. have come/gone out →have been out

4. have become →have been

5. have closed / opened→have been close/open

6. have got up →have been up；

7. have died →have been dead；

8. have left sw. →have been away from sw.

9. have fallen asleep/got to sleep →have been asleep；

10. have finished/ended/completed →have been over；

11. have married →have been married；

12. have started/begun to do sth. →have done sth. ；

13. have begun →have been on

14. have borrowed/bought →have kept/had

15. have lost →haven’t had

16. have put on →have worn

17. have caught /get a cold →have had a cold；

18. have got to know →have known

19. have joined/have taken part in the league/the Party/the army

→have been a member of/ have been in/have been the Party’s member/the league member/the soldier…

注意: since+时间点或者从句，而for +一段时间。Since last year, since 1997, since 8 o’clock a.m. ,since five days ago . for ten years , for an hour .对这类时间状语提问要用how long 。(但how long开始的问句动词要用延续性动词，时态可不限。

eg. How long did he stay there?

We have been friends for many years.

You have been students since two years ago / since 2004./ for two years.

How long have I taught you English ?

I have taught you English since you came to the school.

比较：Mr Black has lived in China since 2000.(从2000年至今还在中国) Mr Black lived in China in 2000.(反正2000年在中国，到底2000年后呢？不得而知)

*在这种用法中，要与一段时间连用，动词必须是延续性的，非延续性的动词只能在否定句中出现，或者变成延续性的动词后也可以。

eg. We haven’t seen each other for some days. See 为瞬间性的动词，但在否定句中也可以和some days 一段时间连用。

3、瞬间性动词和延续性动词的转换。

最常见的瞬间动词如：borrow/lend, buy, die , go/come/leave/arrive/reach, join,begin/start, lose ,fall.get up等。

大家值得注意的是，这类动词不是不可以和现在完成时连用，它们可以用于第一种用法，强调对现在的影响或者结果，但它们不能用于第二种用法与一段时间连用。如：

The man has died. The film has begun.

那么对于上述瞬间性动词，我们可以把它们改成相对应的延续性动词或者表状态的词就可以和一段时间连用了。

Borrow/lend→keep, buy→have, die→be dead, go/leave→be away ,come/reach/arrive/get to →be here/there begin/start→be on /last ,get up →be up ,catch(get )a cold→have a cold, finish →be over ,become→be

eg. a. He has borrowed my English book for two days. (False)

b. He has kept my English book for two days. (true )

a. I have bought the new dress since last month. (false)

b. I have had the new dress since last month. (true)

a. They have left for half an hour . You should come earlier. (false)

b. They have been away for half an hour. You should come earlier.(true)

a. He is an unlucky boy. His mother has died for several years. (false)

b. He is an unlucky boy. His mother has been dead for several years. (true)

a. He has joined the League since he came to the school. (false)

b. He has been a league member since he came to the school. (true)

过去完成时( The Past Perfect Tense )

I.概念:表示在过去某一时间或动作之前已经发生或完成了的动作或状态。它表示句子中描述的动作发生在“过去的过去”。

II.时间状语：before, by the end of last year(term, month…),etc.

III.基本结构：①肯定句：主语+had+过去分词+其他.

②否定句：主语+had+not+过去分词+其他.

③一般疑问句：Had+主语+过去分词+其他?

For example:

By nine o’clock last night, we had got 200 pictures from the spaceship.

到昨晚9点钟，我们已经收到200 张飞船发来的图片。

I had been at the bus stop for 20 minutes when a bus finally came.

当车来的时候，我在车站已等了20分钟。

She found the key that she had lost.她丢失的钥匙找到了。

He said that he had known her well. 他说他很熟悉她。

I saw Li Ping yesterday . We had not seen each other since I left Beijing .

我昨天看见李平了。自从我离开北京，我们就没见过面。

IV.但需要注意下列三种情况不用过去完成时：

1. 句中如有yesterday , last year , in 1986 , three days ago等表示过去时间的状语，谓语动词必须用一般过去时。eg.Peter didn”t play football yesterday .彼得昨天没有踢足球。

2. 汉语中虽然有“了”、“曾”、“过”等字眼表示动作完成，但没有说明动作是在过去某一时间以前完成的，译成英语时要用一般过去时，不用过去完成时。例如：

eg. He went to Beijing the day before yesterday . 前天他去了北京。

3. 叙述在过去连续发生的两件以上的事，虽然在时间上有先后之别，但仍用一般过去时。

eg. They decided to stay here , and so they built their houses and made their farms .

他们决定呆在这儿，所以他们建了房子，开垦了农场。