腾讯通信地址:关于need疑问形式的回答方式？

need既可用作情态动词，又可用作实义动词。
作情态动词时，没有数和人称的变化，后接动词原形。

作实义动词时，有数的变化和人称的变化，后接带to的不定式。

一.用于否定句，表“不必”

例如：

You needn't worry.

你不必担心。

I don't think you need worry.

我想你不必担心。

二.用于疑问句，表“需要吗”

例如：

Need you go? 你得去吗？

No, I needn't. 不必。

Yes, I must. 是的，我必须去。

三.need用作实义动词时，要注意始终以实义动词的标准贯彻到底。 如：

（正确）Do you need to go there?

（错误）Do you need go there?

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1) must表示必须，否定回答时用needn't. mustn't表示不许可。

【例如】

You must get to the station before 3, otherwise you will miss the train.Must I hand in my homework tomorrow?

No, you needn't. You can turn it in the day after tomorrow.

You mustn't smoke in the hospital.

2) must用于肯定句，可以表示推测，翻译为：一定或想必。后面接动词的一般时，表示对现在的推测，接动词的完成式，表示对过去的推测。对过去的推测是考试的重点。

【例如】

She must live near here, for she comes to work on foot.

She was absent from class. There must have been something wrong with her.

The light was out. They must have gone to bed.

Mary's score on the test is the highest in her class. She ____ have studied very hard.(CET-4 1998.1)

A) may

B) should

C) must

D) ought to

“must +不定式完成式”表示对过去发生事情的推测。题意为：玛丽的考试成绩全班第一，她学习一定很刻苦。答案为C.

情态动词的时候就和其他的情态动词一样
Need I go?

作为实意动词的时候就和其他实意动词一样体温
does he need to go?