2."be + 不定式"

"be + 不定式"一种是不定式的谓语用法;另一种是名词性表语,二种是完全不同的.

作为不定式的谓语,可以表达"预定","可能","义务","假设","目的"
,"结果","运命"等,例如:
1.He is to arrive at seven in the morning.(预定)
2.Every misfortune is to be subdued by patience.(可能)
3.You are to stay here till I come back.(命令)
4.It was understood that everybody was to pay his own
expences.(义务)
5.If he were to come,say that I am absent.(假设)
6.This hourse is to be let or sold.(目的)
7.He was to blame for not locking the door.(结果)
8.The worst is still to come.(运命).

不定式作表语用得很多,一般语法书上也都专门谈到.一个典型的例句是:
To see is to believe.(百闻不如一见)
其他有:
1. To do that would be to cut the foot to fit the shoe.
2. Our main task now is to develop the students' ability
to carry on independent work.
当我们用下列词组作主语时常可用不定式作表语:
1.My dream( intention, business, wish, idea, job, work,
task, duty,etc.)
2. What I want to do ( propose to do, plan to do, should
like to do, should advise you to do,etc.)