[Modal auxiliaries] Ability Can and Could

Tom is strong. He can lift that heavy box.	Can is used to express physical ability.
I can see Central Park from my apartment.	Can is frequently used with verbs of the fine senses: see, hear, feel, smell, taste
Maria can play the piano.	Can is used to express an acquired skill.
You can buy a hammer at the hardware store.	Can is used to express possibility.
Tom could lift th box, but I couldn't	The past form of can meaning ability is could.