语法

语法：现在完成时（）

结构：have/has（助动词，无义，只是起到结构上的作用）＋V-ed （过去分词）

附表：过去分词的构成（见上一篇日志）

用法：（一）表示过去的动作对现在造成的影响或结果，强调现在的状态或结果，没有明确的时间状语，常和already，

ever，never, just，yet等副词连用。（already,just只能用于

肯定句中，改否定句和疑问句时，改成yet。ever常用于

否定句和疑问句中。never用于否定句中）此种用法中，

动词可以是短暂动词，也可以是延续性动词。如：

The classroom is so clean . Who ____ (clean) it?

Look! The rain _____(stop). Let’s go fishing.

I_____ (lose) my ticket. I can’t go to the cinema tonight.

It’s cold in the classroom. Who _____(open) the window?

以上几题是语境题，没有明确的时间状语，根据上下文推出动作是过去发生的，对现在造成了“后遗症”，明白了吗？再看几题：

1. I_____ just ___ (have) my supper. 言外之意现在不饿）

2. I ______(see) the film already. （言外之意知道电影内容）

3. ------_________you ______(return )the book to Jack?----- Not yet. (言外之意书仍在我这里)

4. ---_______ you ______(be) late for class? ---No ,never .

5. ______you ever______(read) the story?

比较：1.) -----_________you _____ (buy) a computer?-----Yes.

----- When and where________you ______(buy) it?

----- In the computer shop last Sunday. (注意：when 不能用于现在完成时)

2.) -----_______you _______(see) the film? -----Yes. I ______(see) it last night.

用法二。表示动作从过去开始一直持续到现在，并有可能继续下去，常和一段时间连用。

时间状语：since＋起点；since＋从句；for＋段时间；

in/during/over the past /last few years ，before, recently ,these days ，so far（迄今为止）,how long等表示一段时间的时间状

语，也可以和包括“现在”在内的（到说话时仍未结束）表示一段时间的状语连用。如this morning，today，this week，these days.

I___________(make) many new friends since two years ago.

I___________(make) many new friends for two years.

I___________(make) many new friends since I came here.

★在肯定句中，动词必须用延续性动词，否定句中可以用短暂动词。如：I haven’t seen you for ten years. （√ ）

see 是短暂动词，不能用于肯定句中，但可用于否定句中。

The bus has left for 10 minutes. （×）

The bus has been away for ten minutes. （√ ）

所以，在肯定句中，短暂动词不能和一段时间连用（短和段不连用），必须改成延续性动词。

He has come back.（√）He has come back for two hours.（×）

He has died .（√）He has died for 10 years. （×）

常见的相应转换形式如下:

borrow / lend→keep, buy→have, finish / end→be over, arrive /come / go / move / reach /get to→be in /at / be here /be there, begin / start→be on , open→be open , close→be closed, die→be dead , leave→be away （from）,go to school→be in school / be a student, get up →be up, fall asleep→be asleep , fall ill→be ill, get to know→know, lose→be lost, become→be, return / come back / get back→be back, join→be in / be a…member, join the army→be in the army /be a soldier, receive / get

a letter→have a letter , catch / get a cold→have a cold, begin to study→study,

他参军已有三年.

He has joined the army for three years.（错）

改为:

1.He has been in the army for three years / since three years ago.

2.He has been a soldier for three years / since three years ago.

3.He joined the army three years ago.

4.It is three years since he joined the army.

5.Three years has passed since he joined the army.

（1）He came to our village two years ago.=He our village since two years ago.

（2）He left home three days ago

=He home for 3 days.

（3）I bought the watch 2 weeks ago.=I the watch since 2 weeks ago.

（4）It is 5 days since I borrowed the book.

=I the book for 5 days.

（5）The film has begun= The film for half an hour.

（6）I got to know him 10 years ago.=I him for 10 years.

（7）There is a factory=There a factory for 20 years.

（8）Our school opened in 1960.

=Our school since 1960.

Test (In five minutes)

一．句形转换。

1．He came to China two years ago.

He_____ _____ ______China___two years ago.

It _____ ______ years______he ____to China.

2.We got to know each other in 1995.

We _____ _____ one another _____1995.

3.The man joined the Party ten years ago.

The man_____ ___a Party __ _ ten years ago

The man _____ ___ __the Party__ ten years。

二．改错。

1．I have bought the pen for two years.

2. I have become a middle school student for almost two years.

3.The train has left for ten minutes.

4.The train has left the station for ten minutes.

5.The film has begun for ten minutes.

6.The film has finished for ten minutes.

7. I have got up for half an hour.

8.My mother has gone out for an hour.

9. We have begun to learn English for a year.

10.I have joined the Young Pioneers for three years.