human vs nonhuman

human is a noun but nonhuman is not a noun.

Word	Noun	Adjective	Verb	Adverb
human	Yes	Yes	No	No
nonhuman	No	Yes	No	No

human (noun)	nonhuman (noun)
any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage

human (adjective)	nonhuman (adjective)
having human form or attributes as opposed to those of animals or divine beings	not human; not belonging to or produced by or appropriate to human beings
characteristic of humanity
relating to a person