Zero Conditional

In this lesson, you will learn how to use the zero conditional to talk about things that are always true or happen every time under certain conditions.

1. What Is the Zero Conditional?

The zero conditional is used to talk about:

• things that are always true
• scientific facts and general truths
• habits and routines
• cause-and-effect situations where the result usually or always happens

Key idea: In the zero conditional, both the if-clause and the main clause use the present simple.

If + subject + present simple, subject + present simple

You can start with either the if-clause or the main clause.

• If the if-clause comes first, put a comma after it.
• If the if-clause comes second, do not use a comma.

Examples:

• If you heat water to 100°C, it boils.
• If I drink coffee late, I cannot sleep.
• If it rains, the grass gets wet.

Note: The order of the clauses can change.

• Water boils if you heat it to 100°C.
  (No comma is needed when the if-clause comes second.)

3. Using Zero Conditional

A. Facts & Scientific Truths

• If you mix red and blue, you get purple.
• If you freeze water, it becomes ice.

B. Habits & Everyday Routines

• If I finish work early, I go to the gym.
• If he wakes up late, he misses the bus.

C. Cause and Effect

• If you touch fire, you get burned.
• If you drop a glass, it breaks.

4. Easy Way to Remember

Zero conditional = present simple + present simple = always true

Think: "If this always happens → that always happens."