1.表示按计划或安排要做的事.例如:
When are you to leave for home?你什么时候回家?
She is to get married next month.她下个月结婚.
The Queen is to visit Japan in a week's time.女王将于一周后访问日本.
这种结构也可用于过去.was / were to do sth.表示曾经计划要做某事,但不表明计划是否被执行,或表示"命运(即命中注定要发生的事)",而非计划;was / were to have done sth.表示未曾实现的计划.例如:
I felt nervous because I was soon to leave home for the first time.我感到紧张,因为我很快就要首次离开家了.
We were to have told you,but you were not in.我们本来想告诉你的,但是你不在家.
2.表示"应该",相当于should,ought to.例如:
You are to report to the police.你应该报警.
What is to be done?应该怎么办呢?
3.表示"必须",相当于must,have to.例如:
The letter is to be handed to him in person.这封信必须亲手交给他.
You are to do your homework before you watch TV.看电视之前你得先做作业.
4.表示"想,打算",相当于intend,want.例如:
If we are to be there before ten,we'll have to go now.如果我们想在十点前到,我们现在就得走.
5.用于第一人称疑问句,表示征求对方意见.例如:
Am I to go on with the work?要我继续这项工作吗?
What are we to do next?我们下一步该怎么办?
6.用于否定句,表示"禁止",相当于mustn't.例如:
The books in this room are not to be taken outside.这个室内的书籍不得带出室外.
7.表示"可以,可能",相当于may,can.例如:
The news is to be found in the evening paper.这条消息可以在晚报上见到.
She is nowhere to be found.在哪里也找不着她.
8.were to do sth.用于if或even if / even though从句中,表示对未来的假设.例如:
If I were to tell you that I killed him,would you believe me?要是我告诉你我杀了他,你会相信我吗?
9.be to blame(该受责备,对某坏事应负责任)这种结构用不定式的主动形式表示被动含义.例如:
Which driver is to blame for the accident?这事故是哪个司机的责任?
这是我从网上查的.