auxiliary verb, present singular 1st person can, 2nd can or (Archaic) canst, 3rd can, present plural can; past singular 1st person could, 2nd could or (Archaic) couldst, 3rd could, past plural could.
1.
to be able to; have the ability, power, or skill to:
She can solve the problem easily, I'm sure.
2.
to know how to:
He can play chess, although he's not particularly good at it.
3.
to have the power or means to:
A dictator can impose his will on the people.
4.
to have the right or qualifications to:
He can change whatever he wishes in the script.
5.
may; have permission to:
Can I speak to you for a moment?
6.
to have the possibility:
A coin can land on either side.