deklension

Deklination, in linguistics, refers to the systematic inflection of words to express grammatical categories such as case, number, and gender. The term is commonly used in German grammar, but the underlying concept occurs in many languages, including Latin, Russian, Greek, and Finnish. Deklination covers nouns, pronouns, adjectives, and determiners and governs how their forms change depending on their syntactic role.

The core categories of deklination are case (such as nominative, accusative, genitive, and dative in German), number (singular or plural), and gender (masculine, feminine, neuter). Some languages also mark definiteness or person. Declension patterns are organized into classes or paradigms, often with regular and irregular forms. Nouns can have gender classes that influence their genitive or plural endings; adjectives and articles agree in gender, number, and case with the nouns they modify.

In German, noun declension interacts with article and adjective declension. There are different endings depending on whether a definite article, an indefinite article, or no article accompanies the noun. Adjectives show strong, weak, or mixed declensions depending on the presence and type of determiner. For example: der Mann (nominative singular, masculine with definite article), des Mannes (genitive singular), dem Mann (dative singular), den Mann (accusative singular); die Männer (nominative/plural), der Männer (genitive plural), den Männern (dative plural). Irregular noun plurals and stem changes add complexity.

Declension systems serve to signal grammatical relationships and agreement, guiding sentence structure and interpretation, especially in languages with relatively free word order. Some languages retain rich inflection, while others have largely analytic constructions.