CONDITIONAL SENTECES

UNREAL CONDITIONS

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

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

IMPOSSIBLE or PAST CONDITION

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

If + PAST PERFECT, + WOULD HAVE + VERB (PARTICIPLE)

We also use might have or could have in place of would have

ALWAYS TRUE

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

IF/WHEN PRESENT SIMPLE + PRESENT SIMPLE

REAL CONDITIONS

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

IF PRESENT SIMPLE + WILL FUTURE

We can also use: going to future/ can/could/ might instead of will