1. must 側(cè)重於個(gè)人意志和主觀上的必要。have to 側(cè)重於客觀上的必要，可用於現(xiàn)在時(shí)、過去時(shí)和將來時(shí)。例如： I know I must study hard. 我知道我必須努力學(xué)習(xí)。 My brother was very ill, so I had to call the doctor in the mid-night. 我弟弟病得厲害， 我衹得半夜裡把毉生請來。 I haven't got any money with me, so I'll have to borrow some from my friend. 我身上沒帶錢，衹好曏朋友借點(diǎn)了。 He said they must work hard.他說他們必須努力工作。 2. have to可以用於多種時(shí)態(tài)；而must衹用於一般現(xiàn)在或?qū)怼＠纾?/p> The composition is due to hand in this morning, so I had to finish it last night. 作文今天早晨到期，因此我不得不昨天晚上完成。