英语高手小试牛刀!be to do 与 be going to do 的区别?when从句后为何要用过去完成时?

英语高手小试牛刀!be to do 与 be going to do 的区别?when从句后为何要用过去完成时?
英语高手小试牛刀!
be to do 与 be going to do 的区别?when从句后为何要用过去完成时?

英语高手小试牛刀!be to do 与 be going to do 的区别?when从句后为何要用过去完成时?
一.be to do：
1.表示 “ 将 ” 、 “ 计划 ” 、 “ 安排 ” .( 意思接近于 be going to) 如：
Their daughter is to get married soon.
Who is to question him
It was the last film at the cinema ,which was to close next day.
After dinner they were to go to a movie.
was/ were to do 表示过去曾经计划要做的事,或者过去应当做的事,而且从现在的角度来看已经实现了.如：
I felt nervous because I was soon to leave home for the first time.
I was to play Juliet.
The expedition was to start in a week's time.
was/ were to have done,表示 “ 本打算 ” 、 “ 本计划 ” 或 “ 本应当 ” 做的事而没有做成或没有发生.如 :
I was to have seen him last Wednesday,but he didn't come.
We were to have been married last year.
2.表示 “ 义务 ” 、 “ 应该 ” .( 意思接近于 should ,must ,ought to ,have to) 如：
No one is to leave the building.谁也不得离开这楼房.
You are not to smoke in this room.=You are not supposed to smoke in this room.
You are to be back by 10 o'clock.你必须十点以前回来.
3.表示可能性 ,相当于 can,may 如 :
Such books are to be found in the library.这样的书在图书馆里就能找到.
Not a single sound was to be heard.一点儿声音也听不到.
Not a soul was to be seen.看不到一个人影.
She was nowhere to be found.哪儿也找不到她.
She was never to see his wife and family again.
5.表示 “ 命运 ”,将来必然要发生的事 ,译作 “ 注定 ……” .如：
He came to power,but he was to play dearly for it:soon he was assassinated.
The worst is still to come.
They said goodbye,little knowing they were never to meet again.
6.用于 “if…were to do” ,表示虚拟语气.如：
If it were to rain tomorrow,the sports meeting would be put off.如果明天下雨 ,运动会就会延期.
bo going to：
表示将要发生的事情 或者即将进行的动作
（如果是条件状语从句 主将从现 那个将来时用will do不用be going to~）
二.when
不一定要用过去完成时的 主要是看主句的时态
从句如果用到过去完成时 那主句必定是一个过去的事态 而且主句的动作发生在从句之前~
希望能对你有所帮助哈~

be to do 与 be going to do 为将来的两种表达形式，都可以表示计划、打算好的将要去做的动作。be to do 也可以表示 注定 之意。
如He is to become a famous singer.
when从句后不一定要用过去完成时，当表示过去的过去才用过去完成时，例：区别
I had finished my homework when the ...

全部展开

be to do 与 be going to do 为将来的两种表达形式，都可以表示计划、打算好的将要去做的动作。be to do 也可以表示 注定 之意。
如He is to become a famous singer.
when从句后不一定要用过去完成时，当表示过去的过去才用过去完成时，例：区别
I had finished my homework when the telephone rang.(刚做完）
I was doing my homework when the telephone rang.（正在做）

收起

好像没有be to do 这个说法吧
when后面不一定非要用过去完成时啊