e动词后面的动词形式有三种可能：
-ing:现在进行时, I'm trying to give you the right answer.
-ed:被动语态, I'm told that you don't know her.
to do:
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?
They said goodbye, little knowing that they were never to meet again.他们告了别,不知道以后再也不会见面了.
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.
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.
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.如果我们要在十点前到,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?要我继续完成这项工作吗?
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：
You are not to smoke in the reading-room.你不可以在阅览室里吸烟.
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.
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?要是我告诉你是我杀了他,你会相信吗?
9.be to blame(该受责备,对某坏事应负责任)与be to let(待出租)两种结构中,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?
This house is to let.这房子要出租.
望采纳,谢谢