Vocative case
The vocative case is the case used for a noun identifying the person being addressed, found in Latin among other languages. A vocative expression is an expression of direct address, wherein the identity of the party being spoken to is set forth expressly within a sentence. For example, in the sentence, "I don't know, John.", John is a vocative expression indicating the party who is being addressed.
Some languages (e.g., Greek) have a special vocative case for this; others do not. In Latin the vocative case of a noun is the same as the nominative, except for masculine singular second declension nouns. An example would be the famous line from Shakespeare, "Et tu, Brute?" (And you, Brutus?, commonly translated as You too, Brutus?), where "Brute" is the vocative case, whilst "Brutus" would be the nominative case. When Latin names are translated into English, the nominative case is usually used. English simply uses the nominative case for vocative expressions but sets them off from the rest of the sentences with pauses (rendered in writing as commas). English has some words that are used as vocative markers, as in O Death, where is thy victory, or Hey, you!, but these words are usually classified as interjections.
In English the vocative case is not marked, but English syntax performs a similar function; witness: "John, could you come here?" or "I don't think so, John", where "John" is neither subject nor object of the verb, but rather indicates the person to whom the statement is being addressed.
A vocative expression is interjective and can occur in any clause, irrespective of mood. Some examples...
- Good morning, class!
- Don't forget your swimming trunks, George.
- Hey, George, did you remember to bring your swimming trunks?
- No, Bob, I forgot.
- I'm proud of you, son.
- If I were you, Mary, I'd take French next year instead of Spanish.
- Death, be not proud!