Oops, sorry again, looks like Pollster already covered this. But in reality, about 9 out of 10 of the US population actually uses this phrase incorrectly. I think it's because "could" is just shorter, and one less syllable than "couldn't, so it has stuck. Anyway, I'm just hoping that one day people in the US (I grew up in Canada) figure out how to use the phrase properly, and also that 2 way stops, or intersections without yield or stop signs, are simply not the same as 4 way stops. If we could fix just those two things, I'd have nothing to complain about - JK. Well, except politicians, of course!