If clauses can be REAL or unreal
Grammar books separate them into 4 types:
- Zero conditional – always true. If you let go of an apple it falls to the floor.
- First Conditional – true in that condition. If you don’t turn in you homework, you get a bad grade.
- Second Conditional – unreal in present/future time. If I had enough money, I would go to Japan.
- Third Conditional – unreal in past time. If I hadn’t eaten so much cake, I wouldn’t have gotten sick.
REAL FUTURE “IF” CLAUSES are never written in future verb tense. The verb takes a step back to simple present. Use the “s” form verb with singular subjects.
If the time is future, use “Will” in the main clause, but no “Will” in the if/when condition clause
- If I go see the movie on Saturday, will you go with me?
- If she walks to work, she will need 20 minutes to get there.
If the time is present and the condition is real, use simple present in both clauses.
- If the sun rises in the east, why do we see colors in the western sky?
- If he works in Hayward, he needs the car.
- When he works in Hayward, he needs the car. (when can also be used to mean “in this condition”)
The main clause shows the time.
The REAL IF clause is always in simple present.