Case (grammar)

How case works

Case distinctions are usually realized by suffixes, prefixes or internal changes called affixes, though some languages use separate particles or fixed word order instead. Case tells you what a noun does: for example, a nominative form typically marks the subject, while an accusative marks the direct object. Other typical functions include possession (genitive), indirect object (dative), instrument, location and address (vocative).

• Common case labels: nominative, accusative, genitive, dative, instrumental, locative, vocative.
• Realization: suffixes or clitics; sometimes tonal or vowel changes.
• Interaction: case can affect agreement with verbs, adjectives or determiners.

Case markers signal grammatical relationships that otherwise would be ambiguous. In languages with rich case morphology, word order can be more flexible because case carries much of the syntactic information. In analytic languages, syntactic position and prepositions do similar work.

History and distribution

Case systems are widespread and date back to ancient language families such as Indo-European. For example, Old English had several cases, but Modern English has largely lost case inflection except in pronouns (e.g., he vs. him, she vs. her, they vs. them). Other languages with elaborate case systems include Latin, Russian, Finnish, Hungarian and Georgian. Over time, languages may simplify, repurpose or replace case marking through changes in morphology and syntax.

Uses, examples and distinctions

Case is important for parsing meaning and for typological classification of languages. Examples: in Latin the endings of a noun show whether it is subject or object; in Russian case endings indicate role and sometimes number and gender. In English, possessive 's and objective pronoun forms are the main surviving case marks. Linguists distinguish between morphological case (visible on a word) and abstract syntactic case assigned by sentence structure.

For further study, see entries on inflection, grammatical roles and historical change, or surveys of individual languages and their case patterns: see links on noun morphology, adjective agreement and pronoun paradigms linked here for reference: noun, adjective, pronoun, and general discussions at case overview and inflectional morphology.

Related topics that clarify different angles include studies of affix types, the role of prepositions versus case markers, and historical shifts in case systems across languages (see grammatical signaling and syntax resources).

For historical examples and language-specific descriptions consult specialist grammars and comparative works that treat case systems in detail.