Remember the first conditional is often used to talk about possible future situations and their consequences. Use 'if' for something that you think is likely to happen. Use 'when' if you are certain that something will happen.
Examples:
- If I visit Scotland, I'll see the Loch Ness monster.
- When I visit Scotland, I'll explore the Highlands.
- Alex will phone you, when he gets home from work.
- When we get home tonight, we won't watch TV.
- When you finish university, what will you do?