We use the second/unreal conditional in the following ways:
1 to talk about things that are unlikely to happen in the future:
If I won the lottery, I would travel around the world. (but I don’t know if I will win the lottery)
2 to talk about improbable situations now or in the future:
If he wasn’t so angry, I would talk to him. (but he is angry, so I probably won’t)
We make the second/unreal conditional using this structure:
if + subject + simple past, subject + would/wouldn’t
With the verb to be, we can use either was or were after if. Were is considered more correct and more formal:
If it weren’t / wasn’t so cold, I’d go for a walk in the woods.
We do not normally use would in the if- clause, but we can use it if we are making a formal request:
If you would come with me, please, I’ll show you to the lecture hall.
We can also use the past progressive in the if- clause:
If the children were playing here, it wouldn’t be so quiet.
We can also use could or might in the main clause instead of would:
If we had a computer, we could do this much more quickly.
If you studied more, you might get better grades.
If can be replaced by in case in second/unreal conditional sentences, but is used rarely.
The conditional clause can come before or after the main clause.
Talk to your friends about what you would do if you won a million dollars.