Berlin vs German capital

Berlin and German capital both are nouns.

Word	Noun	Adjective	Verb	Adverb
Berlin	Yes	No	No	No
German capital	Yes	No	No	No

As nouns, Berlin and German capital are synonyms defined as:

Berlin and German capital: capital of Germany located in eastern Germany

Berlin (noun)	German capital (noun)
capital of Germany located in eastern Germany	capital of Germany located in eastern Germany
United States songwriter (born in Russia) who wrote more than 1500 songs and several musical comedies (1888-1989)