过去将来时态在英语中表示过去某个时间点的将来动作，动词变化规则是使用“would”加上动词原形。这种时态常用于虚拟条件句，也可以表达过去的预期或打算。理解其变化规则和用法有助于更好地理解和使用过去将来时态。
动词变化规则
在过去将来时态中，动词需要使用“would”加上动词原形，例如：
- I knew that he would come to the party.
- They said they would help me move.
如果动词是不规则动词，需要使用其过去式加上“would”，例如：
- She said she would eat breakfast early.
- He knew that the car would break down.
用法
过去将来时态通常用于虚拟条件句中，表示“如果…就会…”，例如：
- If I had known you were coming, I would have baked a cake.
- If I had the money, I would buy a new car.
另外，过去将来时态也可以用来表达过去的一种预期或打算，例如：
- We thought that we would have a great time at the beach.
- He said he would finish the project by Friday.
