PART FIRSTWORDS AND FORMS

FOURTH DECLENSION

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 (long).

Nouns of the Fourth Declension are declined as follows:

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

			SINGULAR
			CASE-ENDINGS		CASE-ENDINGS
NOM.	manus	lacus	-us	gen	-
GEN.	mans	lacs	-s	gens	-s
DAT.	manu(-)	lacu(-)	-u(-)	gen	-
ACC.	manum	lacum	-um	gen	-
ABL.	man	lac	-	gen	-
			PLURAL
NOM.	mans	lacs	-s	genua	-ua
GEN.	manuum	lacuum	-uum	genuum	-uum
DAT.	manibus	lacubus	-ibus(-ubus)	genibus	-ibus
ACC.	mans	lacs	-s	genua	-ua
ABL.	manibus	lacubus	-ibus(-ubus)	genibus	-ibus

Gender in the Fourth Declension

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

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

The only Neuters of the Fourth Declension are corn, gen, pec ( 105. f), ver. ⁴⁷

Case-Forms in the Fourth Declension

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

A genitive singular in - (as of the second declension) sometimes occurs in nouns in -tus: as, sentus, genitive sent (regularly sents).

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

The dative and ablative plural in -bus 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.

Most names of plants and trees, and colus, distaff, have also forms of the second declension: as, fcus, fig, genitive fcs or fc.

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

The ablative singular ended anciently in -d (cf. 43. N. 1): as, magistrtd.

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

	SINGULAR	PLURAL
NOM.	domus	doms
GEN.	doms (dom, loc.)	domuum (domrum)
DAT.	domu (dom)	domibus
ACC.	domum	doms (doms)
ABL.	dom (dom)	domibus

NOTE 1.The Locative is dom (rarely domu), at home.

NOTE 2.The Genitive dom occurs in Plautus; domrum is late or poetic. [p. 39]

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, can, sing; csus (for cad-tus), chance, CAD, cad, fall, exsultus, exile, from exsul, to be an exile (exsul).

Many are formed either from verb-stems not in use, or by analogy:
cnsultus (as if from cnsul, -re), sentus, incestus.

The accusative and the dative or ablative of nouns in -tus (-sus) form the Supines of verbs ( 159. b): as, specttum, pettum; dict, vs.

Of many verbal derivatives only the ablative is used as a noun: as, iuss (me), by (my) command; so iniuss (popul), without (the people's) order. Of some only the dative is used: as, dvsu.