national capital vs Bridgetown

national capital and Bridgetown both are nouns.

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

national capital (noun)	Bridgetown (noun)
the capital city of a nation	capital of Barbados; a port city on the southwestern coast of Barbados