Use the comments are said to occur in the future. This means that at a time in the future. I'm doing something for a long time is that more than one will be able to speak one at a time. For example, there is a single event, and 2 there are two events happen just about.
Used to refer to events that are happening in the future means that at a certain period in the future. I am doing something, I will not say more than a long one. For example, to see two types of a single event. The two events occur simultaneously.
.Used to refer to that is going to happen in the future, meaning that at any given time in the future, I'm doing something, which for a long time. So long to say one. For example, for the 2, is a single event.