The nominative and the accusative forms of

- the definite article [= the], e.g. der, die, den

- the indefinite article [= a(n)], e.g. ein, eine, einen

- the negative form of "ein-", e.g. kein, keinen, keinen

 - the possessive article "mein" and "dein" (as examples for all the other possessive articles)

* Unlike ein, kein has a plural form, e.g. Magst du Horrorfilme? -> Ich mag keine Horrorfilme.