Concept
In grammar, the vocative case (abbreviated ) 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 vocative expression 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 vocative expression 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". Historically, the vocative case was an element of the Indo-European case system and existed in Latin, Sanskrit and Ancient Greek. Many modern Indo-European languages (English, Spanish, etc.) have lost the vocative case, but others retain it, including the Baltic languages, some Celtic languages and most Slavic languages. Some linguists, such as Albert Thumb,(de) argue that the vocative form is not a case but a special form of nouns not belonging to any case, as vocative expressions are not related syntactically to other words in sentences. Pronouns usually lack vocative forms. Distinct vocative forms are assumed to have existed in all early Indo-European languages and survive in some. Here is, for example, the Indo-European word for "wolf" in various languages: The elements separated with hyphens denote the stem, the so-called thematic vowel of the case and the actual suffix. In Latin, for example, the nominative case is lupus and the vocative case is lupe, but the accusative case is lupum. The asterisks before the Proto-Indo-European words means that they are theoretical reconstructions and are not attested in a written source. The symbol ◌̩ (vertical line below) indicates a consonant serving as a vowel (it should appear directly below the "l" or "r" in these examples but may appear after them on some systems from issues of font display).