1,在表示一次性動作時,have to和 have got to 是可以互換的：I have (got) to be back by ten o’clock.我必須10點前返回來.I haven’t got to work tomorrow.我明天不必上班.I’ve got to do something!Langdon thought.蘭登想：“我得做點什么!” 2,但是,當表示習慣性動作時,尤其是當句中含有表示經常性的副詞（如always,often,sometimes等）時,則應使用have to ,而不使用have got to:I don’t usually have to work on Sundays.通常我再星期天不必工作.I often have to get up at 5.我常常必須五點起床.3,have to 與 have got to 的另一區(qū)別,就是后者不大用于過去時.They didn’t have to worry about money.他們那時不必為金錢而操心.I had to walk very fast to overtake you.為了趕上你,我不得不走得很快.4,最后一個區(qū)別,就是have to 前可加助動詞或情態(tài)動詞,或者用在進行體和完成體結構中,而have got to卻不能：I shall have to help him as much as I can.我將不得不盡我所能去幫助他.He may have to cancel his plan.他也許不得不取消這個計劃.People are having to boil their drinking water during this emergency.在這個緊急情況下,老百姓必須煮沸他們的飲用水.The administration has had to make unpopular decisions.行政部門不得不做出不得人心的決定.