have to与have got to含义相同，常可以互换。区别在于：
have to构成否定句和疑问句时通常须加do;
have got to 为英国英语在口语中的用法，只需用have或has构成否定句或疑问句，
如：
You don't have to knock—just walk in.
Does she have to stay at home every night?
只是在文语中have to可直接构成问句，
如：
Have we to make our own way to the conference?
Why have you got to take these tablets? 你为什么要吃这些药片？
You haven't got to take flowers but many people do.
你不必非带花去不可，但是许多人都带着花去。
have got to是必须的口语化形式，相当于have to，got to是get to的过去式，表示到达。
have to是情态动词片语，口语中写作have got to，它由have +to组成，因此具有have的各种时式。如：
He is an invalid and has to have a nurse. 他是个病弱之人，需要护士照顾。
She knew what she had to do. 她知道她需要做什么。
I shall have to reconsider my position. 我将不得不重新考虑我的立场。
He is always having to exercise judgment. 他经常需要进行判断。
My impression was that he was having to force himself to talk. 我的印象是，他需要强使自己说话。
I have had to remind you of writing to her all this time. 我不得不老提醒你写信给她。
The people had had to be told that an experiment was taking place that day. 必须通知人们，那天将进行试验。
“As a matter of fact,” he said, “I’ve been having to spend some time with the research people.” “事实上，”他说，“我必须一直同研究人员一起待一些时间。”
It wouldn’t have been very nice for the Davidsons to have to mix with all those people in the smoking-room. 戴维森一家人非得与吸烟间的所有那些人混在一起，是不大好的事。
Having to work alone, he wanted all his time for his research. 他必须单干，所以他想把他的全部时间投入研究工作。
have to的疑问和否定结构多用助动词do构成。如：
Why do I have to do everything? 为什么事事都得我干?
Did he have to tell them about it? 他必须把那件事告诉他们吗?
You don’t have to explain. 你不必作解释了。
There was a grin on his face. He did not have to tell me that he already knew. 他咧嘴而笑。他不需要告诉我他已知道了。
have to的基本用法是：
1)表客观的义务或需要。可用于各种句式，但只用于一般式。如：
He had to do it. 他必须做那件事。
Did he have to do it? 他得做那件事吗?
He did not have to do it. 他不需要做那件事。
在否定句中，have to表不需要，must表不许。试比较：
You don’t have to go there. 你不需要去那儿。
You mustn’t go there. 你不可去那儿。
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ号：24596024