Déclinaison / Conjugueur latin
| SINGULIER |
| Nom. | diphthongus |
| Gen. | diphthongi |
| Dat. | diphthongo |
| Acc. | diphthongum |
| Abl. | diphthongo |
| Voc. | diphthonge |
| PLURIEL |
| Nom. | diphthongi |
| Gen. | diphthongōrum |
| Dat. | diphthongis |
| Acc. | diphthongos |
| Abl. | diphthongis |
| Voc. | diphthongi |
| SINGULIER |
| Nom. | diphthongă |
| Gen. | diphthongae |
| Dat. | diphthongae |
| Acc. | diphthongam |
| Abl. | diphthongā |
| Voc. | diphthongă |
| PLURIEL |
| Nom. | diphthongae |
| Gen. | diphthongārum |
| Dat. | diphthongis |
| Acc. | diphthongas |
| Abl. | diphthongis |
| Voc. | diphthongae |
| SINGULIER |
| Nom. | diphthongum |
| Gen. | diphthongi |
| Dat. | diphthongo |
| Acc. | diphthongum |
| Abl. | diphthongo |
| Voc. | diphthongum |
| PLURIEL |
| Nom. | diphthonga |
| Gen. | diphthongōrum |
| Dat. | diphthongis |
| Acc. | diphthonga |
| Abl. | diphthongis | |