An explanation of the form and use of the zero and 1st conditional in English with examples.

1. ZERO AND 1ST CONDITIONAL
There are severalconditionals in English. They tell us aboutsituations and
their consequences.
They all havea ‘dependent clause’ (usually starting with ‘if’ (sometimes
‘when’ and ‘unless’)) and a ‘main clause’.
Zero Conditional
The structureof the zero conditional is:
(Dependent clause) (Main clause)
When/if/unless + present tense, present tense
We use the zero conditional to talk about something which is always true.
We often use it for talking about science and facts.
When you heat water, you producesteam.
If you don’t eat for a long time, you get hungry.
Unless you put meatin the fridge, it goes off.
Itis possibleto switch the dependentclause and the main clause:
You producesteam when you heat water.
You get hungry if you don’t eat for a long time.
Meat goes off unless you put it in the fridge.
Here you can see when the dependent clause is 1st
, you usea comma. If the
main clause is first, you do not.
Itis also possibleto formthe zero conditional with an imperative in the main
clause:
When you hear a noise, run!
If you see her, say hello.
We can formthe zero conditional in a question (needs ‘if’):
Do you producesteam if you boil water above sea level?
Does meat go off if you don’t put it in the fridge?

2. 1st
Conditional
The structureof the 1st
conditionalis:
(Dependent clause) (Main clause)
If/when + present tense, future tense (or can/must)
We use the first conditional to talk about something that will happen. We
are confident it will happen, although it is not a ‘fact’ as in the zero
conditional. Itis our opinion.
If you go to the party, I will go as well.
If you study hard, you will passthe exam.
If the management changes, the staff can ask for a bonus.
When you go to London, you must go to Hyde Park.
Like with the zero conditional you can swap the dependent clause and the
main clause:
I will go to the party if you go as well.
You will pass the exam if you study hard.
The staff can ask for a bonus if the management changes.
You must go to Hyde Park when you go to London.
The 1st
conditional can also be formed in a question:
Will you go to the party if I go?
Can the staff ask for a bonus if the management changes?