quality vs upper-class

quality is a noun but upper-class is not a noun.

Word	Noun	Adjective	Verb	Adverb
quality	Yes	Yes	No	No
upper-class	No	Yes	No	No

quality (noun)	upper-class (noun)
an essential and distinguishing attribute of something or someone
(music) the distinctive property of a complex sound (a voice or noise or musical sound)
a degree or grade of excellence or worth
a characteristic property that defines the apparent individual nature of something
high social status

quality (adjective)	upper-class (adjective)
of superior grade	occupying the highest socioeconomic position in a society
of high social status