Implicative : “if/when X, Y” = Factual. If X happens, than 100% chance that Y.
Ex: If you put some water in the -30 degree freezer, it will freeze.
Predictive : Hypothetical.
Ex : If my grade are lower than 70%, I’ll take remedial.
Counterfactual/Speculative : Unlikely / false.
Ex : If I had stopped school, I would have worked in an industry.
0 : Present-present (simple)
Ex : If you eat more carbohydrate, you have more energy.
1 : Predictive (present-future)
Ex : If you study harder, you will get higher grades.
2 : Hypothetical (past-future – would)
Ex : If you studied harder, you would get higher grades.
3 : Counterfactual (past perfect)
Ex : If you had finished the homework, you would have submitted it.
Mixed : Mix of 2,3 (counterfactual)
Ex : If you slept in a cooler room, you would have slept well.
If you had checked again your exam paper, you wouldn’t worry much about small mistakes.