Grammatical case

In grammar, the case of a noun or pronoun indicates its grammatical function in a greater phrase or clause; such as the role of subject, of direct object, or of possessor. While all languages distinguish cases in some fashion, it is only customary to say that a language has cases when these are codified in the morphology of its nouns — that is, when nouns change their form to reflect their case. (Such a change in form is a kind of declension, hence a kind of inflection.) Cases are related to, but distinct from, thematic roles such as agent and patient; while certain cases in each language tend to correspond to certain thematic roles, cases are a syntactic notion whereas thematic roles are a semantic one.

Cases in English

Cases are not very prominent in modern English, except in its personal pronouns (a remnant of the more extensive case system which existed in Old English). For other pronouns, and all nouns, adjectives, and articles, case is indicated only by word order, by prepositions, and by the clitic -'s.

Taken as a whole, English personal pronouns are typically said to have three morphological cases: a subjective case (such as I, he, she, we), used for the subject of a finite verb and sometimes for the complement of a copula; an objective case (such as me, him, her, us), used for the direct or indirect object of a verb, for the object of a preposition, for an absolute disjunct, and sometimes for the complement of a copula; and a possessive case (such as my/mine, his, her(s), our(s)), used for a grammatical possessor. That said, these pronouns often have more than three forms; the possessive case typically has both a determiner form (such as my, our) and a distinct independent form (such as mine, ours). Additionally, except for the interrogative personal pronoun who, they all have a distinct reflexive or intensive form (such as myself, ourselves).

Cases in Indo-European languages

Even monument builders have to account for grammatical case. On this memorial sign, commemorating the 500th anniversary of the Russia city of Balakhna, the word Balakhna on the right is in the nominative case, while in 500 Let Balakhne ('500 Years of Balakhna') on the front of the sign the dative is used.

While not very prominent in English, cases feature much more saliently in many other Indo-European languages, such as Latin, Greek, German, Russian. Historically, the Indo-European languages had eight morphological cases, though modern languages typically have fewer, using prepositions and word order to convey information that had previously been conveyed using distinct noun forms. The eight historic cases are as follows, with examples:

• The nominative case, which corresponds to English's subjective case, indicates the subject of a finite verb:

  The man went to the store.

• The accusative case, which together with the dative and ablative cases (below) corresponds to English's objective case, indicates the direct object of a verb:

  The man bought a car.

• The dative case indicates the indirect object of a verb:

  The man gave his daughter a book.

• The ablative case indicates the object of most common prepositions:

  The boy went with his father to see the doctor.

• The genitive case, which corresponds to English's possessive case, indicates the possessor of another noun:

  A country's citizens must defend its honour.

• The vocative case indicates an addressee:

  John, are you O.K.?

• The locative case indicates a location:

  I live in China.

• The instrumental case indicates an object used in performing an action:

  He shot it with the gun.

All of the above are just rough descriptions; the precise distinctions vary from language to language, and are often quite complex. Case is arguably based fundamentally on changes to the ending of the noun to indicate the noun's role in the sentence. This is not how English works, where word order and prepositions are used to achieve this; as such it is debatable whether the above examples of English sentences can be said to be examples of 'case' in English.

Case and linguistic typology

Main article: Morphosyntactic alignment

Languages are categorized into several case systems, based on their morphosyntactic alignment — how they group verb agents and patients into cases:

• Nominative-accusative (or simply accusative): The argument (subject) of an intransitive verb is in the same case as the agent (subject) of a transitive verb; this case is then called the nominative case, with the patient (direct object) of a transitive verb being in the accusative case.
• Ergative-absolutive (or simply ergative): The argument (subject) of an intransitive verb is in the same case as the patient (direct object) of a transitive verb; this case is then called the absolutive case, with the agent (subject) of a transitive verb being in the ergative case.
• Ergative-accusative (or tripartite): The argument (subject) of an intransitive verb is in its own case (the intransitive case), separate from that of the agent (subject) or patient (direct object) of a transitive verb (which is in the ergative case or accusative case, respectively).
• Active-stative (or simply active): The argument (subject) of an intransitive verb can be in one of two cases; if the argument is an agent, as in "He ate," then it is in the same case as the agent (subject) of a transitive verb (sometimes called the agentive case), and if it's a patient, as in "He tripped," then it is in the same case as the patient (direct object) of a transitive verb (sometimes called the patientive case).
• Trigger: One noun in a sentence is the topic or focus. This noun is in the trigger case, and information elsewhere in the sentence (for example a verb affix in Tagalog) specifies the role of the trigger. The trigger may be identified as the agent, patient, etc. Other nouns may be inflected for case, but the inflections are overloaded; for example, in Tagalog, the subject and object of a verb are both expressed in the genitive case when they are not in the trigger case.

The following are systems that some languages use to mark case instead of, or in addition to, declension:

• Positional: Nouns are not inflected for case; the position of a noun in the sentence expresses its case.
• Adpositional: Nouns are accompanied by words that mark case.

Some languages have very many cases; for example, Finnish has fifteen (see Finnish language noun cases) and Tsez can even be analyzed as having 126 cases.

The lemma forms of words, which is the form chosen by convention as the canonical form of a word, is usually the most unmarked or basic case, which is typically the nominative, trigger, or absolutive case, whichever a language may have.

See also

• Agreement (linguistics)
• Declension
• Grammatical voice
• Inflection
• List of grammatical cases
• Thematic role
• Case hierarchy