[Sicon]

I brought him up on it one day at work, and he argued that he was right to use it. I couldn't talk him out of the usage.

Yeah, try it with someone who says "supposably" sometime. "Supposably" is a word, but almost always used incorrectly when the speaker means to say "supposedly".

[driftless2]

"supposably"

To be sure if we could check the speech habits of everybody, we would find we're all (me too) guilty at times of incorrect grammar and butchering the English language. But the "I seen" locution seems to grate on me the most. Especially when used by college grads like my old co-worker.