to be able to; to know how to

She can speak seven languages

I can't make the door open

to have permission to; may

You can go if you want

to have a certain tendency or likelihood

It can be cold at night

used in the negative to express surprise or disbelief

They cannot be serious

Brit, informal (in pl) headphones

NAmer, informal a toilet

chiefly NAmer, informal jail

to pack or preserve (esp food or drink) in a can

chiefly NAmer, informal to put a stop or end to (something)

Can that racket — Nathaniel Bust