Fourth declension nouns are mostly masculine nouns like eventus (event) and risus (laughter).

Here the Latin noun portus (harbor) in the singular:

Nom – portus

Gen – portūs

Dat – portuī

Acc – portum

Voc – portus

Abl – portū

Here is portus (harbor) in the plural:

Nom – portūs

Gen – portuum

Dat – portibus

Acc – portūs

Voc – portūs

Abl – portibus

�