have-to的用法.txt

1、精品文档have to 用法分析have to 是情态动词，意思是“ 必须；不得不” ，表示客观要做的事情，后接动词原形。1、 have to 的单数和复数have to 虽是情态动词， 但有人称或数的变化。 一般现在时第三人称单数用 has to ， 其他人称用 have to 。例如：You have to go with Tom 你得跟汤姆去。She has to answer this question. 她不得不回答这个问题。2、 have to 的肯定式have to 的肯定式由 “ have to+ 动词原形 ” 构成。例如：I have to tell him the news

2、. 我得告诉他这个消息。She has to walk home 她不得不走回家。3、 have to 的否定式have to 的否定式由 “don t have to+ 动词原形 ” 或 “doesn t have to+ 动词 原形 ” 构成。例如：You don t have to do like this. 你不必这样做。He doesn t have to be there on time.他不必按时到那里。have to 的否定式还可在have has 后面加not (仅限于一般现在时和一般过去时)。例如：He hasn t to go there. 他不必去那里。I haven

3、t to get up early. 我不必早起床。4、 have to 的疑问式have to的一般疑问式通常由“Do/ Does +主语+have to+动词原形+其他成分” 构成，肯定回答用 do或does；否定回答用don' t (have to)或doesn' t (have to )。例如：-Do you have to go now? 你现在就得去吗？Yes, I do. 是的。-Does he have to stay home?他必须留在家里吗？-Yes, he does. 是的。( No, he doesn t (have to) . 不，他不必留在家里。

4、5、 have to 的时态have to 可用于各种时态。其一般过去时的肯定式是had to ，否定式是didn thave to ；一般将来时的肯定式是will have to ，否定式是won t have to 。例如：He said he had to see me about something important 他说他有重要的事情 不得不见我。He said they didn t have to borrow 200 yuan from John 他说他们不必向 约翰借二百元。You will have to do that again 你得重做那件事。She won t h

5、ave to go with you. 她不必跟你去。6、 have to 与 must 的区别1. have to 有人称和数的变化， 即第三人称单数用 has to ， 其他人称用 have to ； 而 must 没有人称或数的变化。例如：He has to go there 他必须去那里。She must be off now 她现在必须走了。2. have to 有时态的变化， must 没有。例如：He told me that I must be at the station by ten 他告诉我必须十点前到达车站。He had to pay for it 他不得不赔偿。3. have to 强调客观上 “不得不 ” 做某事； must 指主观上 “必须 ” 做某事。例 如：We must study hard 我们一定要努力学习。He had to go on foot because there was something wrong wi