[KyleGoetz]

Oh yeah, and OP mentions that "can't" and "can" sound the same. I can't speak for other accents, but in the US, the accents I'm familiar with have the stress and pronunciation of the "a" very subtly different.

When I imagine "I can walk on my own," I think of the "a" in "can" as a schwa. /ə/

When I imagine "I can't . . . ," I think of the "a" as something like /æ/.

This is, of course, when just said normally in a sentence.