Zero Conditional
When we use it
We talk about facts, general truths, habits, rules, instructions, and regular patterns.
How it is formed
| if‑part (condition) |
main part (result) |
| if + subject + Present Simple | subject + Present Simple |
If + subject + Present Simple, subject + Present Simple.
Subject + Present Simple + if + subject + Present Simple.
If water reaches 100°C, it boils.
If water reaches 100°C, it boils.
Notes
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You can swap the parts
If you heat ice, it melts.It melts if you heat ice.
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Use a comma only when the if‑clause comes first
If you heat ice, it melts.It melts if you heat ice.
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Common with time conjunctions: when, whenever, unless
When it rains, the ground gets wet.When it rains, the ground gets wet.Unless plants get light, they don’t grow.Unless plants get light, they don’t grow.
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Imperative result for instructions
If you see an error, report it.If you see an error, report it.
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Don’t use will (this is not about the future, but about facts)
❌ If you heat ice, it will melt.✅ If you heat ice, it melts.
Negation in Zero Conditional
-
In the if‑clause: Present Simple + don’t / doesn’t
If he doesn’t call, he gets worried.If he doesn’t call, he gets worried.
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In the main clause: normal Present Simple negation
If plants don’t get light, they don’t grow.If plants don’t get light, they don’t grow.
Questions in Zero Conditional
What happens if + Present Simple?
Wh-word + Present Simple + if + Present Simple?
What happens if it rains?
What happens if it rains?
Why does water boil if it reaches 100°C?
Why does water boil if it reaches 100°C?
Where do you go if you finish work early?
Where do you go if you finish work early?
Common mistakes
❌ If it will rain, the ground gets wet.
✅ If it rains, the ground gets wet.
❌ Comma always: It melts, if you heat ice.
✅ Comma only if the if‑clause comes first.
❌ Imperative in the if‑clause: If you report it, … (not a rule)
✅ If you see an error, report it.
More examples
If I am late, my boss gets angry.
If I am late, my boss gets angry.
If you press this button, the app opens.
If you press this button, the app opens.
If it rains, people usually take umbrellas.
If it rains, people usually take umbrellas.
If plants don’t get light, they don’t grow.
If plants don’t get light, they don’t grow.
Structure: If + Present Simple → Present Simple
Facts, habits, instructions, regular patterns
No will in either clause