national capital vs capital of Uruguay

national capital and capital of Uruguay both are nouns.

Word	Noun	Adjective	Verb	Adverb
national capital	Yes	No	No	No
capital of Uruguay	Yes	No	No	No

national capital (noun)	capital of Uruguay (noun)
the capital city of a nation	the capital and largest city of Uruguay; a cosmopolitan city and one of the busiest ports in South America