You can tell a Canadian accent typically if they sound mildly retarded. People from the South tend to sound mildly retarded too, but they're easy enough to distinguish from the Canadians. Having grown up in northern Minnesota, I guess the Minnesotan accent does sound a bit dumb, not as dumb as Canada though. Really, it's more grating than anything.
Also, if you ever see Income Properties on HGTV, the host, Scott McGillivray is pretty obviously Canadian sounding. No American speaks like that. For the love of God, he pronounces progress as pro-gress (emphasis on the 'pro', eep!) instead of praw-gress.
The Simpsons said:Bart: So, what are you in for?
Gordy: I moved here from Canada, and they think I'm slow, eh?
Also, if you ever see Income Properties on HGTV, the host, Scott McGillivray is pretty obviously Canadian sounding. No American speaks like that. For the love of God, he pronounces progress as pro-gress (emphasis on the 'pro', eep!) instead of praw-gress.