Welcome to the Grammar Minute, where we’re saving the English language sixty seconds at a time! I’m Lauren Smyth, and I’m here to tell you that you can jump up on a table in the middle of class and start playing the electric guitar. Chances are, though, you don’t have permission to do this. And so, even though you can, you may not.
Informal English often gives “can” and “may” the same meaning. “You can have a cookie” implies both that you have the possibility of eating that cookie and the permission to do it. Often, though, this distinction is meaningful. There are many things you have permission but not possibility to do, and often things you have possibility but not permission to do. If you want to distinguish, use “can” and “may” carefully.
“Can” implies possibility. “May” implies permission. They’re similar, but they don’t quite mean the same thing.
That’s your Grammar Minute! Visit thegrammarminute.com for more tips and tricks.