Conditional sentences consist of two or more clauses. One of the clauses is the “if clause” and the other is the “main clause”. In the first conditional, b0th if clause and main clause are usually in Present Simple Tense.
If I can’t sleep, I listen to the radio.
The zero conditional is used for talking about things that are generally true. It often refers to natural truths, such as scientific facts:
Ice melts if you heat it.
If you water the grass, it grows.
In zero conditionals, it is not about the past, present or future, it is about a result that is always true for that condition.
Paul always phones me if he is bored.
Children make a snowman if there is enough snow.
We can also use imperative instead of Present Simple Tense in the main clause:
If Jane calls, tell her where I am.
If the doorbell rings, don’t answer it.
We can use “when ” instead of “if” without the difference in meaning:
When the weather is nice, we usually go for a walk.
My mum cries when she is sad.
Note: use a comma at the end of an if-clause, when an if-clause is at the beginning of the sentence.
When you get near my house, please call me.
Do the quiz to perfect your knowledge of the Zero Conditional: