must 和 have to的用法區(qū)別

1. must 側重於個人意志和主觀上的必要。have to 側重於客觀上的必要，可用於現(xiàn)在時、過去時和將來時。例如：

I know I must study hard. 我知道我必須努力學習。

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可以用於多種時態(tài)；而must衹用於一般現(xiàn)在或將來。例如：

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。