作者：丁德田
1. be+to do表示"將要做......"
He is very happy to be a student in the university. 將要成為大學生，他感到非常高興。
2. have (has) + to do表示"不得不做......"
It is late now. He has to go home. 天晚了，他不得不回家去。
I have to stop my car and wait for the policeman. 我不得不停車等那個警察。
3. there be ... + to do表示"有......要做"
There is nothing important to do today. 今天沒有什么重要的事要做。
There are lots of letters to post now. 現在有許多信要寄。
4. be about+to do表示"正要做......"
She was just about to leave when someone called her. 正要離開，忽然有人給她打電話。
Hurry up!The match is about to begin. 快點，比賽就要開始了。
5. only+to do表示"卻......"
She went home in a hurry only to find that nothing happened there. 她匆忙回家，卻發現那兒什么事都沒有發生。
He lifted a stone only to drop it on his own feet. 他搬起了石頭卻砸了自己的腳。
6. so as(not)+to do表示"為了（不）......"
She worked hard so as to be a college student. 為了上大學，她努力學習。
He went to work early so as not to be late. 為了不遲到，他很早就去上班了。
7. enough+to do表示"十分......，足夠......"
The girl isn't old enough to go to school. 這個女孩還不到上學的年齡。
8. It is (was)+形容詞 + of(for)sb. + to do ... 表示"（某人）做某事很......"。
It is wise of you to do so. 你這樣做很明智。
It's very hard for you to get there on foot. 對你來說，步行到那兒是非常艱難的。