Zero conditional
A2 ElementaryThe zero conditional describes general truths, scientific facts, and habits that always happen under specific conditions. It uses the present simple in both parts of the sentence.
Overview
The zero conditional is used to talk about things that are always true. It describes real-world facts, scientific laws, or personal routines where one action automatically causes another. Because these situations are certain, the word if can often be replaced by when without changing the meaning.
Form
If + present simple, present simple
Both the condition (the 'if' clause) and the result (the main clause) use the present simple tense. If the 'if' clause comes first, use a comma. If the result comes first, no comma is needed.
Examples
Common mistakes
If you will heat water to 100 degrees, it boils.
If you heat water to 100 degrees, it boils.
Do not use 'will' in the zero conditional because it describes a general fact, not a specific future event.
If it rains the grass got wet.
If it rains, the grass gets wet.
Both verbs must be in the present simple to show a constant relationship.
Practice
Complete the sentence: If you ____ (mix) red and blue, you get purple.
Show answer
mix
Answer:mix
Why:The zero conditional uses the present simple in the 'if' clause to describe a factual result.
Complete the sentence: Snakes bite if they ____ (feel) scared.
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feel
Answer:feel
Why:This is a general truth about animal behavior, so the present simple is required.
Rewrite using 'if': When it rains, the ground gets wet.
Show answer
If it rains, the ground gets wet.
Answer:If it rains, the ground gets wet.
Why:In the zero conditional, 'if' and 'when' are interchangeable because the result is always the same.