1、
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。
一、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。
二、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.我得告诉他这
2、个消息。
She has to walk home.她不得不走回家。
三、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’t to ge
3、t up early.我不必早起床。
四、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:
①–Do you have to go now?你现在就得去吗?
–Yes, I do.是的。
②–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。]
五、have
4、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’t have 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 have t
5、o go with you. 她不必跟你去。
六、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 with his car.因为他的汽车坏了,他不得不走着去。