national capital vs Kinshasa

national capital and Kinshasa both are nouns.

Word	Noun	Adjective	Verb	Adverb
national capital	Yes	No	No	No
Kinshasa	Yes	No	No	No

national capital (noun)	Kinshasa (noun)
the capital city of a nation	the capital of the Democratic Republic of the Congo on the Congo river opposite Brazzaville