Use (May) and (Can)
May: it is used for (permission) (request) and (imagination).
Example: May i come in sir?
May i go to drink water (permission).
May i take your pen?
May i do this work? (request)
My brother may come today from delhi.
It may rain today. (imagination)
Note: from all these sentences you are trying to take permission/ request/ from someone and wait for their reaponse.
Can: it is used to express your power ability.
Example: I can do this work
I can beat you.
I can speak english
You can run fast
I can swim.
Note: From all these sentences you are trying to express your power ability to do anything.
Hope....
You have got understood. See you in the next lesson my dear students. Till then bay for now.
Thank you...........