Kasussystem

Kasussystem, in linguistics, refers to the set of grammatical cases that a language uses to mark the roles of noun phrases and to express relationships between sentence elements. Cases are typically realized as inflectional endings on nouns or pronouns, or as separate prepositions or periphrastic forms in analytic languages. The Kasussystem influences morphology and syntax, including agreement with adjectives and pronouns and the relative freedom of word order.

Most languages with case systems exhibit a nominative–accusative or an ergative–absolutive alignment, though many show more complex or mixed patterns. In nominative–accusative languages, the subject of both intransitive and transitive verbs bears the nominative, while the direct object bears the accusative. In ergative–absolutive languages, the subject of intransitive verbs and the object of transitive verbs bear the absolutive, while the agent of a transitive verb takes an ergative case. Some languages rely more on word order or prepositions than on morphology to express function, producing a spectrum from synthetic to analytic systems.

Common cases include nominative, accusative, dative, genitive, and locative or instrumental. Additional cases may mark possession, direction, or other semantic roles. The distribution and number of cases vary widely: languages such as Russian or Finnish have rich case inventories, whereas some languages have four or fewer, and others rely on prepositions alone.

Historical development shapes a Kasussystem. Cases may merge or split over time, or become less productive and be replaced by prepositional or periphrastic forms through language contact and simplification. The Kasussystem thus reflects both historical change and current syntactic organization.