Zero Conditional If-Clauses in English Grammar

What is the zero conditional?

Zero conditional sentences express things that always happen providing a certain condition is met. This condition is expressed in the if-clause.

Example:
If you leave ice cream in the sun, it melts.
You get ice if you freeze water.

Both clauses contain the present tense.

When to use zero conditional if-clauses

We use zero conditional if-clauses to talk about:

  • facts
Example:
If you heat water, it boils.
  • habits
Example:
If it is warm, I go to the beach.
  • rules
Example:
Children can ride the rollercoaster if they are over 140cm tall.

How to form the zero conditional

The zero conditional is the easiest conditional structure; we use the present tense in both the if-clause and the main clause.

Example:
If you heat water, it boils.

We can reverse the order of the clauses without any change in meaning.

Example:
If you take the bus, you need a ticket. = You need a ticket if you take the bus.

When the if-clause comes first, it is followed by a comma. If the order is reversed, we do not use a comma.

Examples:
If I have time, I go to the gym after work. (comma after if-clause)
I go to the gym after work if I have time. (no comma)

If, when and whenever

Zero conditional if-clauses express almost the same meaning as time clauses with when and whenever. When emphasises the certainty of an action.

Example:
Harry feels better if he exercises. = Harry feels better when he exercises.

Whenever means at any time or every time when.

Example:
Whenever it is warm, I go to the beach.

Learn more about the difference between when and if.