keinen

Keinen is the accusative masculine singular form of the German determiner kein, used to negate a noun. It corresponds to English "no" or "not any" and appears whenever the noun is masculine and in the accusative case. Kein functions as a determiner that goes with a noun; it does not stand alone the way some pronouns do. The form ke in en is one of several inflected forms that mirror the pattern of ein.

Declension (summary):

- Masculine: Nominative kein; Accusative keinen; Dative keinem; Genitive keines.

- Neuter: Nominative kein; Accusative kein; Dative keinem; Genitive keines.

- Feminine: Nominative keine; Accusative keine; Dative keiner; Genitive keiner.

- Plural: Nominative keine; Accusative keine; Dative keinen; Genitive keiner.

Usage examples:

Ich habe keinen Hund. (I have no dog.)

Sie hat keinen Plan. (She has no plan.)

Wir sehen keinen Film. (We are not watching a film.)

Ich habe keinen Zweifel. (I have no doubt.)

Keinen negates a noun in the accusative masculine singular, while the other genders and numbers use entsprechende Formen: keine for feminine or plural, kein for neuter, with the appropriate case endings. In contrast to nicht, which negates verbs, adjectives, or entire clauses, kein negates the existence or quantity of a noun. Keinen appears frequently in everyday German, in phrases such as keinen Sinn or keinen Zweck, to express absence or negation of a specific item.