need的语法

用法一: need后接动词原形的用法

need用作情态动词，意思是“必要”、“必须”，其后接动词原形，通常只用于否定句、疑问句以及if或whether之后。如:

You need not tell the entire truth, but you must not lie.你不必说出全部真相，但你一定不许撒谎。

Need you go so soon? 你非得这么快就走吗?

So I needn't tell her, need I?所以我无须告诉她，是吗?

I need hardly tell you that the work is dangerous.无须我说你也知道那工作的危险性。

一Need I come tomorrow?我明天需要来吗?

一Yes, I must.是的。需要。

They wonder whether need wait for her.他们不知道是否要等她。

need有时用于含有only, all等限制意义的肯定句中。如:

If you want anything, you need only ask.你想要什么只要打个招呼就行。

All you need do is to take a taxi from the airport.你从机场乘出租汽车即可。

(2) need用作实意动词，意思是“需要”，和不定式连用。如:

We need to work harder.我们必须更加努力工作。

These flowers need to be watered three times a week.这些花一周需要浇三次水。

What do you need to take with you on business?你出差需要带什么东西?

Does he need to know?他需要知道这件事吗?

I don't think you need to worry in the least.我认为你一点儿也没必要着急。

They didn't need to arrive so early.他们没有必要来的那么早。

用法二: need 后接完成式的用法

need / needn’t+动词完成式表示过去“需要/不需要做某事，但实际未做/做了”。如:

Need you have bought so much rice?你当时有必要买那么多大米吗?

You needn't have told him the news; he knew it already.你不必告诉他这个消息，他已经知道了。

He needn't have come in person, a telephone would have been enough.他本来没有必要亲自来，打个电话就可以了。

It is Sunday. You needn't have woken me up so early.今天是星期日，你没必要这么早就叫醒我。

-Need he have come so early?他来那么早有必要吗?

- Yes, he had to. / No, he needn't have.有必要，他必须来那么早。/不，他本来没有必要来那么早的。

用法三:need 后接进行的用法

need+动词进行式,表示正在进行的动作。如:

We needn't be standing here in the sun.我们没有必要站在这里晒太阳。

完