The case of direct address.
Direct address is the idea in each construction. This is the only use of the Vocative Case.
The Use of the Interjection ῶ with the Vocative
This use gives a kind of solemnity where it is found. It expresses feeling in most of its occurrences. It may have a tone of censure. It was sometimes used in formal address. In the N.T. it adds emphasis. It only occurs 17 times in the N.T.
Apposition to the Vocative
The Nominative and Vocative are freely used side by side in apposition. Two Vocative forms may also be used appositionally.
The Vocative in the Predicate
This use is rarely found in the N.T. and then only in the nature of quotations or translation.
Occasionally an adjective in the vocative case is found.
The Article Used with the Vocative
The article is used with the Vocative to ascribe special definiteness to the object of address. This use occurs 60 times in the N.T.