| Regenechtheit | Nominativ, Singular | nominative case, singular | |
| Regenechtheite | Genitiv, Singular | genitive case, singular | |
| Regenechtheiten | Dativ, Singular | dative case, singular | |
| Regenechtheit(e)s | Akkusativ, Singular | accusative case, singular | |
| Regenechtheiter | Nominativ, Plural | nominative case, plural | |
| Regenechtheitern | Genitiv, Plural | genitive case, plural | |
| Regenechtheitn | Dativ, Plural | dative case, plural |