100 % zeker gevolg = If + present simple, +present simple
if water reaches 100 degrees, it boils
waarschijnlijk gevolg = if + present simple, + will (not) hele ww
If she walks in now, I will yell at her.
onwaarschijnlijke situatie = if + past simple + would (not) hele ww
If I won the lottery, I would give all of you money.