| Singular | Plural | |
|---|---|---|
| Nominativ | efficax | efficacia, efficaces |
| Genitiv | efficacis | efficacium |
| Dativ | efficaci | efficacibus |
| Akkusativ | efficax, efficacem | efficacia, efficacis, efficaces |
| Ablativ | efficaci | efficacibus |
| Vokativ | efficax | efficacia, efficaces |
| Singular | Plural | |
|---|---|---|
| Nominativ | efficacius, efficacior | — |
| Genitiv | — | — |
| Dativ | — | — |
| Akkusativ | efficacius | — |
| Ablativ | efficaciore | — |
| Vokativ | efficacius, efficacior | — |
| Singular | Plural | |
|---|---|---|
| Nominativ | efficacissimum, efficacissima, efficacissimus | efficacissimae, efficacissima |
| Genitiv | efficacissimae | — |
| Dativ | efficacissimae | efficacissimis |
| Akkusativ | efficacissimam, efficacissimum, efficacissimum | efficacissima, efficacissimas |
| Ablativ | efficacissima | efficacissimis |
| Vokativ | efficacissime, efficacissimum, efficacissima | efficacissimae, efficacissima |