have与must在英语中有什么不同呀

have to 约等于must
have to与其要委婉一点
must则强硬一点

must强调主语的主观的"必须"

比如"i must go now for i am hungry"这里在客观上他并不一定要走,但是由于他饿了,他自己觉得必须走了,所以是must

另外must可以用做命令."you must go now!"而have to则不行

must还可以在肯定句中起推断的作用
比如"he must be there,is he?"表推断,他一定在那,对吗? 而have to 同样不行

have to强调主语客观的必须

比如"i have to go now or i will be killed by my mother"这里,是由于客观上有某件事情或某个东西,所以必须要走,无论主观上想不想,都必须.

这里举个小对话,比如你(例子而已)上课想去WC,给老师说"sir! i must go out now!"老师会问你"do you really have to?"呵呵,明白了吧

mustn't表示,"一定不行",而don't have to 表示不需要.

比如 you mustn't run againt the traffic light你一定不能闯红灯!!
you don't have to finish it in such a short time.你并不需要在那么短的时间内完成它!
这两题：
Look! The traffic light is red. I must stop my car.(主观）
It's still early. You don't have to hurry 。don't have to 表示不需要.

主观 和 客观