| Nominativ | quartusdecimum, quartusdecimus, quartusdecima | quartusdecimae, quartusdecimi, quartusdecima |
| Genitiv | quartusdecimae, quartusdecimi, quartusdecimi | quartusdecimorum, quartusdecimorum, quartusdecimarum |
| Dativ | quartusdecimo, quartusdecimo, quartusdecimae | quartusdecimis |
| Akkusativ | quartusdecimam, quartusdecimum, quartusdecimum | quartusdecima, quartusdecimos, quartusdecimas |
| Ablativ | quartusdecimo, quartusdecimo, quartusdecima | quartusdecimis |
| Vokativ | quartusdecime, quartusdecimum, quartusdecima | quartusdecima, quartusdecimae, quartusdecimi |
