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