national capital vs Malabo

national capital and Malabo both are nouns.

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

national capital (noun)	Malabo (noun)
the capital city of a nation	the capital and largest city of Equatorial Guinea on the island of Bioko in the Gulf of Guinea