| Singular | Plural | |||
|---|---|---|---|---|
| Caz | Articulat | Nearticulat | Articulat | Nearticulat |
| Nominativ | heptaoxidul | heptaoxid | heptaoxizii | heptaoxizi |
| Acuzativ | heptaoxidul | heptaoxid | heptaoxizii | heptaoxizi |
| Genitiv | heptaoxidului | heptaoxid | heptaoxizilor | heptaoxizi |
| Dativ | heptaoxidului | heptaoxid | heptaoxizilor | heptaoxizi |
| Vocativ | ||||