一般过去将来时
形式：would+动词原形和was/were going to+动词原形
用于描述过去某时间里你对于未来的想法和猜测。

过去进行时
形式：was /were + V-ing
表示在过去某一时刻或某一段时间内进行或发生的动作。

例句对比：
（1）
We were going to have supper when the phone rang. 我们将要吃晚饭的时候电话响了。
We were having supper when the phone rang. 我们正在吃晚饭时电话响了。

（2）
I was going to read books when Jack came back. 杰克回来的时候我正要去看书。
I was reading books when Jack came back. 杰克回来的时候我正在看书。

（3）
She was having a lot of trouble with her heart. So, she said she would go to the hospital. 她有很严重的心脏病，所以她说她要去医院看看。
She went to the doctor yesterday. She was having a lot of trouble with her heart.她昨天去看病了。她有很严重的心脏病。

注意：少数动词可以使用过去进行时来代表过去将来时，如：go, come, arrive, leave, start等严格按照时间起止的动词。

让我们来通过例句感受一下：

（1）Lots of people were coming to buy chocolates. 许多人要来买巧克力。

（2）My sister told me that the train was leaving at 8 the next morning. 我姐姐告诉我火车会在明早8点出发。

（3）They wanted to know when we were leaving for another city. 他们想知道我们什么时候去另一个城市。

如何？同学们记住使用过去进行时代替一般过去将来时的用法了吗？