Modals Can/Could

Ability
Can Could Be able to
I can run very fast
I could run faster when I wasn’t so tired
I was able to outrun my P.E. teacher once
I will be able to do it again if I start practicing

Probability
Can Could May Might
It can happen
It couldn’t happen even if we all wanted
He may be at home now
He might be at home, but I’m not sure

Permission
Can Could May
Might (SUPER POLITE)
Can you help me with this?
Could I borrow your book?
May I borrow your book?
I wonder if I might borrow your book
Can you …. ? May I….. ?