We can also use: going to future/ can/could/ might instead of will
If X happens, Y will happen. These sentences describe what the speaker thinks will possibly happen as a consequence of a real situation. Ex.:If we do not deal with the global warming problem, temperatures will rise
REAL CONDITIONS
ZERO CONDITIONAL
IF/WHEN PRESENT SIMPLE + PRESENT SIMPLE
If X happens, Y happens. These sentences describe what always happens in certain circumstances, e.g. scientific facts: Ex.: When/ if you press the switch, the light comes on
ALWAYS TRUE
Topic principal
THIRD CONDITIONAL
If + PAST PERFECT, + WOULD HAVE + VERB (PARTICIPLE)
We also use might have or could have in place of would have
If X happened, Y would have pappened. These sentences describe what the speaker thinks would have happened as a consequence of a situation which is in the past, so it´s impossible to change. Ex.: If I'd seen you, I would have said hello
IMPOSSIBLE or PAST CONDITION
SECOND CONDITIONAL
IF PAST SIMPLE + WOULD +VERB (BASE FORM)
The past simple tense we use in an If- clause does not describe past time, but unreal time. We use also might or could in place of would
If X happened, Y would happen. These sentences describe what the speaker thinks would happen in an imaginary situation. Ex.: If you were in Venus, you would see the sun rise in the west
