STRUCTURE OF CONDITIONALS

1. ZERO CONDITIONAL.

We use the structure:
If + present simple + present simple.
ex: If it rains, you get wet.

We can reverse the order:
present simple + if + present simple.
ex: Plants die if they don't get enough water.

2. FIRST CONDITIONAL.
we use the structure:
If + present simple + will/won´t.
ex:If they do not pass their exam, their teacher will be sad.

we can reverse the order:
If + will/won´t + present simple.
ex: He´ll invite Julia if she is free tomorrow.

3. SECOND CONDITIONAL.
We use the structure:
If + past simple + would(or ´d)
ex: If I had a million dollars, I would buy a big house.

4. THIRD CONDITIONAL.
We use the structure:
If + past perfect + would have (or´d have) + past pasticiple.
ex: If I had won the lottery, I would have bought a car.