The zero conditional is a structure used for talking
about general truths — things which always happen under certain
conditions. This page will explain how the zero conditional is
formed, and when to use it.
1. The structure of a zero conditional sentence
A zero conditional sentence consists of two clauses, an “if”
clause and a main clause (In most zero conditional sentences you
can use when or if and the
meaning will stay the same.):
|If you heat water to 100
If the “if” clause comes first, a comma is usually used. If
the “if” clause comes second, there is no need for a comma:
||if you heat it to 100
We use the same verb form in each part of a zero conditional:
the simple present tense:
|if + subject
+ simple present verb
|subject + simple present verb
2. Using the zero conditional
The zero conditional is used to talk about things which are
always true — such as scientific facts and general truths:
|If you cross an international
date line, the time changes.
||This always happens — every
time you cross a date line.
|If it rains, the grass gets
||This is basically always true
— the rain makes the grass wet.
|Wood doesn't burn if there is
||This is a scientific fact —
wood needs air in order to burn. No air = no fire.
When you are sure that you understand the lesson, you can
continue with the exercises.