i think abbastanza is an adverb. In this particular sentence "sufficiente" is an adjective..so i don't think that would work.
The hover over says "adequate" is a translation of sufficiente but my answer was wrong when I wrote " it is almost adequate." Anyone know why?
Maybe it's because that sounds awkward in English. There are better ways to say the same thing.
"About enough" and "almost enough" are the same ()*&&^@# thing! Curses again! Sometimes Duo is very permissive, and sometimes it's downright pedantic.