What is a noun in the vocative case?
Any noun not preceded by an article or other determiner is in the vocative case. It is most often used to address someone or some group of living beings, usually in conjunction with an imperative construct.
What is vocative case in Old English?
Noun. (grammar) case of address, case used for a noun identifying the person or thing being addressed. It corresponds to the archaic English particle "O" as used in solemn or poetic address e.g.: Hear me, O Albion!
What is the vocative rule?
Vocative Case: The Basics
The vocative case is used for direct address. In other words, if you are speaking directly to someone, any term that you use to refer to them must be in the vocative. Usually you address someone by their name, but you might also use a term of endearment or an insult.