previous next


88. The Stem of nouns of the Fourth Declension ends in u-. This is usually weakened to i before -bus. Masculine and Feminine nouns form the nominative by adding s; Neuters have for nominative the simple stem, but with ū (long).

89. Nouns of the Fourth Declension are declined as follows:

manus , F., hand lacus , M., lake genū , N., knee
STEM manu- STEM lacu- STEM genu-

NOM. manus lacus -us genū -ū
GEN. manūs lacūs -ūs genūs -ūs
DAT. man-ū lac-ū --ū genū -ū
ACC. manum lacum -um genū -ū
ABL. manū lacū -ū genū -ū
NOM. manūs lacūs -ūs genua -ua
GEN. manuum lacuum -uum genuum -uum
DAT. manibus lacubus -ibus-ubus genibus -ibus
ACC. manūs lacūs -ūs genua -ua
ABL. manibus lacubus -ibus-ubus genibus -ibus

Gender in the Fourth Declension

90. Most nouns of the Fourth Declension in -us are Masculine.

Exceptions: The following are Feminine: acus , anus, colus , domus , īdūs (plural), manus , nurus, porticus , quīnquātrūs (plural), socrus , tribus , with a few names of plants and trees. Also, rarely, penus , specus .

91. The only Neuters of the Fourth Declension are cornū , genū , pecū (§ 105. f), verū.1

Case-Forms in the Fourth Declension

92. The following peculiarities in case-forms of the Fourth Declension require notice:—

a. A genitive singular in -ī (as of the second declension) sometimes occurs in nouns in -tus: as, senātus , genitive senātī (regularly senātūs ).

b. In the genitive plural -uum is sometimes pronounced as one syllable, and may then be written -um: as, “ currum (Aen. 6.653) for curruum .

c. The dative and ablative plural in -ŭbus are retained in partus and tribus; so regularly in artus and lacus , and occasionally in other words; portus and specus have both -ubus and -ibus.

d. Most names of plants and trees, and colus, distaff, have also forms of the second declension: as, fīcus, fig, genitive fīcūs or fīcī.

e. An old genitive singular in -uis or -uos and an old genitive plural in -uom occur rarely: as, senātuis, senātuos; fluctuom.

f. The ablative singular ended anciently in -ūd (cf. § 43. N. 1): as, magistrātūd.

93. Domus (F.), house, has two stems ending in u- and o-. Hence it shows forms of both the fourth and second declensions:

Note 1.--The Locative is domī (rarely domuī ), at home.

Note 2.--The Genitive domī occurs in Plautus; domōrum is late or poetic.

NOM. domus domūs
GEN. domūs (domī, loc.) domuum (dom ōrum
DAT. dom (dom ō domibus
ACC. domum domōs (dom ūs
ABL. domō (dom ū domibus

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

  1. 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:

  1. 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 (mycommand; so iniussū ( populī ), without (the people's) order. Of some only the dative is used: as, dīvīsuī .

1 A few other neuters of this declension are mentioned by the ancient grammarians as occurring in certain cases.

hide References (1 total)
  • Cross-references from this page (1):
hide Display Preferences
Greek Display:
Arabic Display:
View by Default:
Browse Bar: