Zero conditional (if + present, present) expresses general facts and habits: If you heat water, it boils.First conditional (if + present, will) expresses real, likely future situations: If it rains, I'll stay home.
Exercises:
Exercise 1 (Easy): Zero Conditional: facts and habits
Choose the correct verb form to complete the zero conditional sentence (if + present simple, present simple).
Exercises:
1
If you heat water to 100°C, it ___.
2
Plants ___ if they don't get enough water.
3
If you ___ ice, it melts.
4
She always ___ a headache if she doesn't sleep enough.
5
If you mix red and blue, you ___ purple.
6
Metals ___ when you heat them.
7
If I drink coffee late, I ___ sleep.
8
If you ___ a dog, it trusts you.
9
The engine ___ if there's no oil.
10
If you ___ in the sun too long, you get sunburned.
Zero & First Conditional
Facts & habits vs real future possibilities
Zero Conditional: General Truths
If+Present Simple,Present Simple
✅
If you heat water to 100°C, it boils.
✅
Plants die if they don't get enough water.
✅
If you mix red and blue, you get purple.
Use: facts, scientific laws, general truths, habits. Always true.
First Conditional: Real Future
If+Present Simple,will+verb
✅
If it rains, I'll take an umbrella.
✅
If she studies hard, she'll pass the exam.
✅
We'll miss the train if we don't leave now.
Use: real, likely future situations. The condition might actually happen.
!Quick Reference
Type
If clause
Main clause
Use
Zero
If + present simple
present simple
General truths
First
If + present simple
will + verb
Real future
Common Mistake
❌
If it will rain, I'll stay.
✅
If it rains, I'll stay.
Remember: NEVER use "will" in the if-clause of the first conditional. The if-clause always takes the present simple, even when talking about the future.