There are four conditional patterns in English. Generally you learn about first and second conditionals at the pre-intermediate level. Sometimes teachers mention the zeroeth conditional. The third conditional is often saved for later because it seems complicated.
With the /'zi roʊθ/ conditional, the condition is purely a logical link, not a temporal one. hehe... not so simple, the zeroeth conditional, huh?. In other words if is equivalent to when or whenever... i.e. (à) chaque fois
- If you snooze, you lose.
- If she doesn't practice, she gets rusty.
Notice that the verbs are conjugated in the standard present tense. (3rd person -s) The present progressive (be + -ing) is not common with the 0th conditional, because the 0th is outside of time.
The first conditional is very common and refers to specific and sometimes unforeseen events, not generalities:
- If you wait here, I'll get the zombies for you.
- If you don't wait here, the zombies'll get you for me.
- Don't worry! They can't hear you or smell you if you stay right there.
Any present tense verb (simple, be + -ing, have + -en) can be used in the if-clause (called the protase). One of three modals (can, may, will) is used in the other clause (called the apodose).
This is very similar to French.
- If you're coming to the dinner tonight, he may be there.
- I'll take the newspaper if you've finished with it.
Some liberty is allowed beyond those three modals of course:
- If you wait here, the zombies should be along shortly.
- You might want to wait to buy it, if you think you can get a better deal elsewhere.
- You could wait to change cars, if you think the price will come down.
- You really must go to Vienne or Nîmes, if you want to see some cool Roman relics.
The second conditional is counter-intuitive, because you use the past to speak about a potential future:
- If she had a million dollars, she wouldn't buy a yacht.
- She might be more tempted, if she had a hundred million dollars.
- You could make bills, if you had a better-paying job.