If he looked hungry, I'd probably give him some money.
If they still lived in their house, would the have raised any money?
What would you do if you saw a homeless person on the street?
PRESENT
If you'd been in the car with Hannah, what would you have done?
PAST
if + past perfect; Modal + v.s.form
if + past perfect; modal + present perfect
MIXED PRESENT AND PAST
Maybe. But they might not be so close now if they had stayed there.
I might not have thought about it if she hadn't mentioned it.
if + v.s.past; Modal+ present perfect
if + v.s. past; modal + v.s. form
