| Formaldehyd | Nominativ, Singular | nominative case, singular | |
| Formaldehyd(e)s | Genitiv, Singular | genitive case, singular | |
| Formaldehyd(e) | Dativ, Singular | dative case, singular | |
| Formaldehyd | Akkusativ, Singular | accusative case, singular | |
| Formaldehyde | Nominativ, Plural | nominative case, plural | |
| Formaldehyde | Genitiv, Plural | genitive case, plural | |
| Formaldehyden | Dativ, Plural | dative case, plural | |
| Formaldehyde | Akkusativ, Plural | accusative case, plural |