The Future Real Conditional describes what you think you will do in the future.
(Look at example 1)
It is different from other Real Conditional forms because you do not know what will happen in the future, you must guess.
It is called "real" because it is still possible or likely that the action will happen in the future.
Both "if" and "when" are used with the Future Real Conditional. Using "if" says that you do not know if an action will happen or not. "When" says that an action will happen; but you are waiting for that action to occur. (Look at example 2 and 3)
1. When I run the marathon tomorrow, I will be tired when I finish.
2. If I study English, I will be fluent.
3. When Tom travels to France, he will take a plane.
*Remember: "When" is %100 - you are sure the action will happen.
*Remember: "If" is 50% - you are not sure an action will happen.