What is It?
It is used to show that in the past, a speaker thought about something that would happen in future. It does not matter if it is true or false.
When to Use?
* To express confidence or a suggestion about future events.
– I knew that the surrounding people would call for an ambulance, so I did not stay at the car accident site.
* To show an intention that had place in the past.
– He thought that I was going to come to a party, so he reserved me a table.
The future in the past tense cannot be used with words and phrases that express time, such as with when, while, before, after, if, unless, during, as soon as.