| Singular | Plural | |
|---|---|---|
| Nominativ | tonitrus | tonitrus, tonitruus |
| Genitiv | tonitri, tonitrus, tonitros | tonitrum, tonitruum |
| Dativ | tonitrui, tonitruque, tonitru | tonitrubus, tonitribus, tonitribusque |
| Akkusativ | tonitrum | tonitruus, tonitrus |
| Ablativ | tonitru, tonitruque | tonitrubus, tonitribus, tonitribusque |
| Vokativ | tonitrus | tonitruus, tonitrus |