When you are writing or speaking and you want to convey an idea of something that usually, generally or always happens, use the zero conditional. This conditional is used, for example, to talk about scientific facts.
The formula for the zero conditional is:
if/when + simple present (1st clause) + simple present or an imperative (2nd clause)
Zero conditionals have a time frame that is NOW / ALWAYS and REAL / POSSIBLE. They do not discuss future or past.
- When people eat too much, they put on weight.
- If people eat too much, they put on weight.
- People put on weight if they eat too much. (No comma when if is in the middle of the sentence)
- If you leave, Peter is in charge.
- When you leave, Peter is in charge.
- Peter is in charge if you leave. (Notice again there is no comma)
- If granny cooks, we all eat like kings.
- When granny cooks, we all eat like kings.
- We all eat like kings when granny cooks. (No comma)
- “If I speaks, you listen,” said the king.
- “When I speak, you listen,” said the king.
- The king said when he speaks you listen.
So as you practice these remember there are two clauses. The first if- clause can be replaced by the word when-. The second clause (the main clause) is always the result of the first clause (see my examples above again). Should the words if/when appear in the middle of the sentence no comma is required.
Something else that is interesting about the zero conditional is how the words IF and WHEN mean exactly the same thing. It doesn’t matter which you choose to use, the meaning will always be the same. This doesn’t happen at other times because IF and WHEN do not mean the same thing (except in zero conditionals).
Right, now it’s your turn. Complete the following for some more practice:
- When you cut your finger,
- If water and electricity mix,
- When water boils,
- When cats are happy,
- If we don’t eat,
- When you study hard,