Kasusmarkering

Kasusmarkering, or case marking, is a linguistic phenomenon in which languages mark noun phrases to indicate their grammatical roles in sentences. Markers may be affixes (suffixes, prefixes, or circumfixes), internal vowel changes (abla), or separate words such as prepositions or articles that attach to the noun phrase or determine its relation to the verb. Some languages rely predominantly on morphology, while others use word order and prepositions to signal case.

The most common cases include nominative (subject of a verb), accusative (direct object), genitive (possession), and dative (indirect object). Many languages also have instrumental, locative, or ablative cases, among others. The exact inventories differ widely: some languages have large case systems; others have only a handful or none, with pronouns retaining more marking in languages with reduced noun case.

In typology, case marking interacts with syntactic alignment. Nominative-accusative languages mark the subject of intransitive and transitive verbs similarly (nominative) and mark direct objects with accusative. Ergative-absolutive languages mark the subject of transitive verbs differently from the subject of intransitive verbs and from objects. English uses limited case marking mainly on pronouns; many other languages—German, Russian, Finnish, Turkish, among others—exhibit richer case systems.

Case marking supports flexible word order, disambiguates the thematic roles, and encodes grammatical information such as number and possession. Over time, languages may lose or reduce case endings, introduce analytic prepositions, or shift toward fixed word order, illustrating the dynamic nature of kasusmarkering.