Accepted now (or soon, at least).

"śpieć" and "śpiewać" respectively

Yeah, but it's too much for "źle", I would put "fatalnie" for terribly.

Perhaps "poorly" is closer to the meaning of "źle".

One is a word, the other is not ;)

my interpretation: zły -> angry zly I didn't know was a word. Did you mean źly ? Then that would mean -> "wrong (m)"