Many English speakers are confused about the usage of the words 'can'
and 'may'. For e.g., 'Can I drink water?' is incorrect. 'May I
drink water?' is the correct phrase to use in this case.
The key difference between 'can' and 'may' is that 'can' talks about
ability and 'may' talks about permission.
To talk about ability.
To ask or give permission informally.
Let us take a situation between a student and a teacher.
Let us take a situation between two strangers.