for present, real/factual situations
If I drink coffee at night,
I
don’t sleep well.First Conditional -
used for future real/factual situations
If I drink coffee tonight,
I won’t sleep well.
Second Conditional -
used for present or future unreal, imaginary situations
If I drank coffee tonight,
I wouldn’t sleep well.
If I had drunk coffee last night,
I wouldn’t have slept well.
Third Conditional -
used for past unreal, imaginary situations