How to distinguish between American and Canadian

My American friend enlightened me the other day and showed me that we Canadians have a grammatical structure that Americans don't use! Maybe not all of you will say this, but my section of the population does (maybe western Canada or young adult):

• I'm done my homework.
• When you're done that, let me know.
• I'm done lunch.

All of these have BE+done. Of course, I never thought it to be strange, because I have always used this construction! My American friend said that she would use HAVE+done or BE+finished, but never a mix of the two. So, I suppose we have one more criterion to add to the list that we use to tell a Canadian from an American!