We use the zero conditional when the result of the condition is always true, like a scientific fact.
Take some ice. Put it in a saucepan. Heat the saucepan. What happens? The ice melts (it becomes water). You would be surprised if it did not.
IF CONDITION RESULT PRESENT SIMPLE PRESENT SIMPLE IF YOU EAT ICE, IT MELTS IF I GET SICK, I GO TO THE DOCTOR IF PEOPLE DON’T EAT, THEY GET HUNGRY IF I AM LATE FOR WORK, MY BOSS GETS ANGRY IF YOU EAT ICE, DOES IT MELT? RESULT IF CONDITION PRESENT SIMPLE PRESENT SIMPLE ICE MELTS IF YOU EAT IT I GO TO THE DOCTOR IF I GET SICK PEOPLE GET HUNGRY IF THEY DON’T EAT MY BOSS GETS ANGRY IF I AM LATE FOR WORK DOES ICE MELT IF YOU HEAT IT?
Notice that we are thinking about a result that is always true for this condition. The result of the condition is an absolute certainty . We are not thinking about the future or the past, or even the present. We are thinking about a simple fact. We use the present simple tense to talk about the condition. We also use the present simple tense to talk about the result. The important thing about the zero conditional is that the condition always has the same result .
Here is a chart to help you to visualize the basic English conditionals. Do not take the 50% and 10% figures too literally. They are just to help you.
PROBABILITY CONDITIONAL EXAMPLE TIME 100% ZERO If you heat ice, it melts. ANYTIME 50% FIRST If it rains, I will stay at home. FUTURE 10% SECOND If I won the lottery, I would buy a car. FUTURE 0% THIRD If I had won the lottery, I would have bought a car. PAST
1 What would you do if it ( will rain / would rain / rained ) on your wedding day?
2 If she comes I ( would / will / would have ) call you.
3 If I eat peanut butter I ( would get / would have gotten / get )sick.
4 What will you do if you ( you would fail / will fail / fail ) the history exam?
5 If they had not ( taken / take / would take )the car I would have driven you.
6 If it snows ( will you / would you / would you have )still drive to the coast?
7 He would have ( go / going / gone ) with you if you had asked him.
8 If I won a million dollars I ( will buy / would buy / would have bought ) my own airplane.
9 If I forget her birthday Andrea ( gets / would get / would have gotten ) upset.
10 Jacob will pick you up at school if it ( will rain / rains / rained )