User:SOTO/Forum Archive/Help!/@comment-43874324-20200702151414/@comment-1296654-20200823144507

Exactly. You are A. Adjectives are not countable.

"You are a beautiful" [adjective] doesn't make sense. "You are a beauty" [noun] does.

It's not a case of "believing" that they are nouns. They objectively, definitively, literally are.