英语现在完成时讲解

现在完成时

1．构成：

助动词（第一、第二人称单复数以及第三人称复数）have /（第三人称单数）has +过去分词”否定句形式：是在have/has后直接+not；疑问句形式：把have/has提前。

肯定回答：Y es,主语+have/has. 否定回答：No,主语+haven’t/hasn’t.

现在完成时用于描述一个发生在过去，并一直延续到现在，或者可能还要延续到将来的动作。

e.g. I called her just now. （过去时）/ I have just called her.（现在完成时）

They have worked in the factory for ten months by now.从句中得知：他们在工厂干活这个动作始于十个月前，这十个月来他们一直在工厂干活，换而言之，这个动作从过去一直延续到了现在。

e.g. We have learned English for nearly 3 years.学英语这个动作开始于3年前，三年来一直在学，也就是说学英语这个动作从三年前一直延续到现在。

2．常与现在完成时连用的时间状语有：

already , yet , never , ever , just , before , in the last/past 10 years , so far , since+点时间, for+段时间等等。

1) already , just用语肯定句中：

e.g. --Would you like to see the film?

--No, I’ve already seen it. / No, I have seen it already. / No, I have just seen it.

（言下之意：已知内容，无须再看。）

2) yet用于有already的句子变成的否定句或者疑问句中，放在句尾。

e.g. I have already milked the cow. （我已经挤过牛奶了。）

→ Have you milked the cow yet? –No, I haven’t done it yet. / No, not yet.

Have you had lunch yet?

3) never用于否定句或者否定回答中。ever用于疑问句中表示“曾经……吗？”

e.g. I have never lost a library book before.

→ Have you ever lost a library book? –No, never.

4) before用于句末。

e.g. The woman has never heard of you before.

5) so far用于句首或句末。

e.g. So far, we have traveled to the moon.

6) in the past/last…years用于句末。

e.g. I have learned more than 2000 new words in the last/past 3 years.

7) for+一段时间（句中动词必须是延续性动词）

since+起点时间（句中动词必须是延续性动词）

since+一段时间+ago（句中动词必须是延续性动词）

e.g. I have taught English for 9 years (since 9 years ago).

He has read newspaper for 3 hours (since 3 hours ago).

He has been in his school since 1999.

I have known him since 20 years ago (for 20 years).

*since+从句（从句用过去时态）

e.g. I have lived here since I was born.

He has worked in this factory since he left college.

3．非延续性动词在现在完成时中的用法：

有些动词是瞬间动词（也叫非延续性动词），这些动词的动作是一发生就结束了，这些动作可用于现在完成时，但是不能跟表示一段时间的状语连用，例如：for … / since … / so far / up till now / up to now / in the past/last …years 等等。

e.g. He has become a doctor. → He has been a doctor for 5 years.

His grandfather has died . → His grandfather has been dead for 10 years.

Wu Peng has joined the League. → Wu Peng has been a league member for 3 years.

The film has finished . → The film has been over for 1 hour. The film has begun . → The film has been on since 1 hour ago.

has left home. → Tom has been away from home for 3 weeks(since 3 weeks ago).

opened 3 years ago. → The factor has been open for 3 years.（过去式和现在完成时的互换）

综述：短暂性动词若要与表示一段时间的状语连用构成现在完成时have/has been+形

He has gone to Beijing.（他已经去北京了。）→ He has been in Beijing for 3 days.

He has been to Beijing.（他去过北京了。） （误）→（正）

Great changes have taken place in my hometown in the past/last 5 years.

This is the most beautiful mountain I have ever seen .

最高级 + 现在完成时