- The zero conditional describes situations that are always true.
- ‘ If ‘ can be replaced by when or whenever without changing the meaning of a given sentence.
The zero conditional is made up of two present simple verbs:
- the ‘if’ clause in the present simple
- the main clause in the present simple.
- If you park your car on double yellow lines, you pay a fine.
(Whenever you park illegally, you pay a fine.)
- If water reaches 100 degrees, it boils.
(It is always true, there can’t be a different result sometimes).
- You get water if you mix hydrogen and oxygen.
(It’s always true!)
- If they go to school, they get up at seven.
(Whenever they go to school they get up at the same time.)
- My friends always help me if I ask them.
(My friends help me whenever I ask them.)
Apart from the basic forms (the present simple in the main clause and the if clause),
we can use other verb forms in the zero conditional sentences:
- If you want to be healthy, you must exercise.
(a modal verb in the main clause)
- If you are tired all day long, sleep more!
(an imperative in the main clause)
‘ If ‘ is the most frequent expression in the if clauses, but other expressions are also possible. even if, provided (that), unless, on condition (that)
- Iron melts on condition that it is heated..
- He never says hello unless you say hello to him first.
- Meat goes off provided that we don’t keep it in a fridge.
- the teacher always shouts even if there’s no need.