§94. Case-Forms in the Fourth Declension

Most nouns of the Fourth Declension are formed from verb-stems, or roots, by means of the suffix -tus (-sus) (§ 238. b):

• cantus, song, CAN, canō, sing; cāsus (for † cad-tus), chance, CAD, cadō, fall, exsulātus, exile, from exsulō, to be an exile ( exsul).

a. Many are formed either from verb-stems not in use, or by analogy:

• cōnsulātus (as if from †cōnsulō, -āre), senātus, incestus.

b. The accusative and the dative or ablative of nouns in -tus (-sus) form the Supines of verbs (§ 159. b): as, spectātum, petītum; dictū, vīsū.

c. Of many verbal derivatives only the ablative is used as a noun: as, iussū ( meō), by (my) command; so iniussū ( populī), without (the people's) order. Of some only the dative is used: as, dīvīsuī.