Porto vs city

Porto and city both are nouns.

Word	Noun	Adjective	Verb	Adverb
Porto	Yes	No	No	No
city	Yes	No	No	No

Porto (noun)	city (noun)
port city in northwest Portugal; noted for port wine	people living in a large densely populated municipality
	a large and densely populated urban area; may include several independent administrative districts
	an incorporated administrative district established by state charter