have to的否定形式

have to的否定形式是don't/ doesn't/ didn't have to,没必要，相当于 needn't. You don't have to go there.= You needn't go there.= You don't need to go there= It is unnecessary for you to go there.你没必要去那。

have to的否定形式

have to 的否定式是 don't have to，相当于 needn't，译为“不得不”，例如：

You don't have to be alone with him and I don't think you ought to be.

你不必单独跟他呆在一起，而且我认为你也不该这样。

You don't have to shout at me.

你没必要朝我嚷嚷。

have to的用法

1、have to 意为"必须、不得不"，相当于一个情态动词，后接动词原形，have 有人称、数和时态的变化。

Dale was ill yesterday, so he had to stay at home.

戴尔昨天生病了，因此他不得不呆在家里。

He'll have to look after his little sister at home tomorrow.

明天他不得不在家照看他的妹妹。

My brother has to do some washing by himself.

我弟弟不得不自己洗衣服。

2、含有have to 的否定句和疑问句必须借助助动词do 的适当形式。have to 的否定形式表示"没必要、不必"，相当于needn't。例：

Do you have to finish the work today?

你们今天必须完成这项工作吗？

You don't have to hand in your homework right now.

你们不必马上交作业。

—Does he have to go there at once? —No, he doesn't （have to）。

—他必须立刻去那里吗？ —不，不必。

have to 与 must的区别

1、have to 强调客观需要，而 must 着重说明个人主观看法。

My mother is ill. She has to stop working.

妈妈病了，她不得不停止工作。

We must finish our homework first.

我们必须先完成作业。

2、have to 有人称、数和时态的变化，而 must 则没有。

Mary had to finish watering those flowers.

玛莉必须浇完那些花。

He must go to school earlier tomorrow.

他明天必须早点去学校。

3、must 可以表示推测，意为"肯定、一定"，而 have to 则没有。

The schoolbag must be Gina's.

这个书包一定是吉娜的。