Future in the past is used when you want to discuss something in the past that you thought would happen in the future. It doesn’t matter whether the thing actually ended up happening. You use future in the past to discuss a plan or a promise from the past.
There are two ways to form the future in the past. One way is to use was/were going to, as in, “He was going to go to the movies last Friday night.” At some point in the past, he had a plan to go to the movies last Friday night. “Last Friday night” falls sometime between the moment when he made the plan and now.
You can also use would to form future in the past. Use would when you are talking about something in the past that someone promised or volunteered to do. For example, you might say, “He said he would call when he arrived.” If the call happened, it happened after he said he would.
Future in the Past Lessons: