American English vs upward

American English is a noun but upward is not a noun.

Word	Noun	Adjective	Verb	Adverb
American English	Yes	No	No	No
upward	No	Yes	No	Yes

American English (noun)	upward (noun)
the English language as used in the United States

American English (adjective)	upward (adjective)
	extending or moving toward a higher place
	directed up

American English (adverb)	upward (adverb)
	spatially or metaphorically from a lower to a higher position
	to a later time