Vocative case

In grammar, the vocative case (abbreviated voc) is a grammatical case which is used for a noun that identifies a person (animal, object, etc.) being addressed or occasionally for the noun modifiers (determiners, adjectives, participles, and numerals) of that noun. A noun of address is an expression of direct address by which the identity of the party spoken to is set forth expressly within a sentence. For example, in the sentence "I don't know, John," John is a noun of address that indicates the party being addressed, as opposed to the sentence "I don't know John", in which "John" is the direct object of the verb "know". As observed by Zwicky, vocative case is used to express at least two functions: (i) as a call aimed to attract the attention of an unratified overhearer, as (ii) address to maintain and perform the social relation towards the hearer. Some authors including Gutzmann assume that so-called expressive vocatives are further distinct vocative function. Historically, the vocative case was an element of the Indo-European case system and existed in Latin, Sanskrit, and Ancient Greek. In many modern Indo-European languages (English, Spanish, etc.) the vocative case has been absorbed by the nominative, but others still distinguish it, including the Baltic languages, some Celtic languages, Modern Greek and most Slavic languages. Some linguists, such as Albert Thumb, argue that the vocative form originated as the bare form of a noun when it does not belong to any case, and that its vocative role came about because nouns of address do not play a syntactic role in relation to other words in sentences; since case suffixes mark these syntactic roles, one was not required. Pronouns usually lack vocative forms.