THE ZERO CONDITIONAL

    In 'zero' conditional sentences, the tense in both parts of the sentence is the simple present:

'IF' CLAUSE (CONDITION)	MAIN CLAUSE (RESULT)
If + simple presentIf you heat ice If it rains	simple presentit melts. you get wet

NOTE: The order of the clauses is not fixed - the 'if' clause can be first or second:

• Ice melts if you heat it.
• You get wet if it rains.

    In these sentences, the time is now or always and the situation is real and possible. They are used to make statements about the real world, and often refer to general truths, such as scientific facts.

Examples:

a. If you freeze water, it becomes a solid.
b. Plants die if they don't get enough water.
c. If my husband has a cold, I usually catch it.
d. If public transport is efficient, people stop using their cars.
e. If you mix red and blue, you get purple.

The structure below is often used to give instructions, using the imperative in the main clause:

• If Bill phones, tell him to meet me at the cinema.
• Ask Pete if you're not sure what to do.