一、过去将来完成时和过去将来时在时间上是一致的，都表示过去某段时间看将来的事情，只是，过去将来完成时更强调的是“完成”，某件事在过去的时间看将来的事情已经完成了。
1.I thought Tom would have told our teacher some bad things about us.
我想汤姆肯定会告诉老师咱们的坏事的。
2.He knew by the time he arrived she would have prepared everything for you.
他知道他到时她肯定准备好了一切事情。
二、而过去将来时并无这一层的意思，它单单指的是过去的时间看将来的事情。例如：
1、由助动词“would/should+动词原形”构成,should主要用于主语是第一人称时;would可用于各种人称。
1）Whenever we had trouble, he would come to help us.
不论何时我们遇到困难,他总会给予帮助。
2）He said he would come to see me.
他说他要来看我。
3）He told me he would go to Beijing.
他告诉我他将去北京。
2、由“was/were going to+动词原形”构成。
1）No one knew when he was going to come.
没有人知道他什么时候来。
2）She said she was going to start off at once.
她说她将立即出发。
3）I was told that he was going to return home.
有人告诉我他准备回家。
3、come， go， leave， arrive， start等动词可用过去进行时代替过去将来时。例如:
1）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。
2）She told me she was coming to see me.
她告诉我她要来看我。