例：I have been staying with my family on the coast.

He has been learning English for 6 years.

温馨提示：

现在完成时：强调动作开始于过去，并持续到现在或过去的动作对现在产生影响。

现在完成进行时：强调动作的持续性，需使用延续性动词。

例：I have broken a teapot.

I have been practicing the piano.

一， 现在分词的完成式

1. 构成：having done

2. 用法：having done表示的动作发生在谓语动词的动作之前。现在分词的完成式主要用作状语，

表示时间，原因等。

①表示时间：Having noted down our names and addresses, the policeman dismissed us.

②表示原因：Having been there once, she knew the place quite well.

3. 现在分词一般式与完成式的区别"

现在分词一般式所表示的动词先于谓语动词发生，但两者之间没有时间间隔；而现在分词的完成式所表示的先于谓语的动作则与谓语的动作有时间间隔。

例：Locking the door, she went out.

Having lost his job, he began to interest himself in local voluntary work.

延续性动词的现在分词一般式往往表示动作在发生过程中谓语动词动作发生，而当现在分词动作在谓语动作前发生且持续一段时间时，必须用现在分词的完成式。

例：Having been his own boss for such a long time, he found it hard to accept orders from others.

Searching the room, he found a wallet.

二， 情态动词+have done

1. 情态动词can/could(not), may/might(not)和must与have done连用，表示对过去事情的推测。

He may/might not have known about it.

2. 情态动词could(not), should(not)与have done连用，翻译为"本...".

You should have faced the difficulty together, but why didn't you tell me?

例 1. -Tommy is planning to buy a car.

-I know. By next time month, he _____ enough for a used one.

A. saves

B. saved

C. will save

D. will have saved

解析：句意：-Tommy正计划着买一辆车。-我知道。到下个月，他将攒够足够的钱买一辆二手车。由by next month可知用将来完成时。