过去将来时表示在过去某个时间看来将要发生的动作或存在的状态。过去将来时常用于宾语从句和间接引语中。例如：
I didn’t know if he would come.
我不知道他是否会来。
They never knew that population would become a big problem.
他们从来都不知道人口问题将会成为一个大问题。
She didn’t tell me where she would go.
她没有告诉我她要去哪儿。
Betty said she would visit the Great Wall next Saturday.
贝蒂说下周六她要去参观长城。
二、过去将来时的表达法
（一）“would+动词原形”。常表示按计划或安排即将发生的事。例如
He said he would come to see me.
他说他要来看我。
He told me he would go to Beijing.
他告诉我他将去北京。
（二）“was/ were+going to+动词原形”。常可用来表示按计划或安排即将发生的事。例如：
She said she was going to start off at once.
她说她将立即出发。
I was told that he was going to return home.
有人告诉我他准备回家。
此结构还可表示根据当时情况判断有可能但不一定会发生某事。例如：
It seemed as if it was going to rain.
看来好像要下雨。
（三）come， go， leave， arrive， start等动词可用过去进行时代替过去将来时。例如：
He said the train was leaving at six the next morning.
他说火车将于第二天早晨六点离开。
She told me she was coming to see me.
她告诉我她要来看我。
（四）条件状语从句和时间状语从句中须用一般过去时代替过去将来时。例如：
I didn’t know when she would come， but when she came I would let you know.
我不知道她什么时候来，但她来了我会告诉你。
The teacher said that it would be very difficult to make progress if I didn’t work hard.
说，如果我不努力的话，就很难取得进步。
过去将来时典型错误例析
1. 我们不知道他是否要在会上发言。
误：We didn&rsquo 初中历史;t know whether he is going to speak at the meeting.
正：We didn’t know whether he was going to speak at the meeting.
析：该句主句为过去时，且宾语从句表示从过去某个时间看来将要发生的动作，所以从句要用过去将来时态。
2. 老师问汤姆长大后准备干什么。
误：The teacher asked Tom what he was going to be when he would grow up.
正：The teacher asked Tom what he was going to be when he grew up.
析：在时间状语从句中，常用一般过去时表示在过去看来将要发生的动作。
3. 他们说如果下星期天不下雨他们就去农场。
误：They said that they were going to the farm if it would not rain the next Sunday.
正：They said that they were going to the farm if it didn’t rain the next Sunday.
析：在条件状语从句中，也常用一般过去时表示在过去看来将要发生的动作。
4. 王林打电话告诉她妈妈，她要买一些书。
误：Wang Lin rang up to tell her mother that she should buy some books.
正：Wang Lin rang up to tell her mother that she would buy some books.
析：过去将来时可以由“助动词should/would+动词原形”构成，但should一般只用于第一人称。而would可用于各种人称。
5. 上次我见到你时，你正打算开始乘火车去西藏。
误：Last time I saw you， you had started to go to Tibet by train.
正：Last time I saw you， you were going to start to go to Tibet by train.
析：last time是一般过去时或过去将来时的显著标志。
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