4th Declension Nouns - Examples and Practice

Let's decline a few fourth declension nouns to review the general rules for noun formation. The basics: take the noun base and add your declension endings.

Example nouns:

metus, metus, m. - fear
- Base: met-
cornu, cornus, n. - horn, wing (of an army)
- Base: corn-

**Fourth Declension Noun Examples**
	metus, metus, m.		cornu, cornus, n.
Case	Singular	Plural	Singular	Plural
Nominative	metus	metus	cornu	cornua
Genitive	metus	metuum	cornus	cornuum
Dative	metui	metibus	cornu	cornibus
Accusative	metum	metus	cornu	cornua
Ablative	metu	metibus	cornu	cornibus
Vocative	metus	metus	cornu	cornua

The Irregular Noun domus

There is one irregular 4th declension noun that will need to be looked at more carefully: domus, domus, f. - house. This noun can use both 2nd and 4th declension endings. For instance, the genitive singular can be both domus (4th declension) but also domi (2nd declension). In the chart below, both declensions are presented side by side. Are there any forms that can only be 4th declension? Are there any that are only 2nd declension?

domus, domus/domi - home
- Base: dom-
- Note: the base is dom regardless of whether you use the 2nd or 4th declension genitive:
  - domi - i = dom-
  - domus - us = dom-

Fourth Declension Irregular Noun *domus*
	2nd declension forms		4th declension forms
Case	Singular	Plural	Singular	Plural
Nominative	domus	domi	domus	domus
Genitive	domi	domorum	domus	domuum
Dative	domo	---	domui	domibus
Accusative	domum	domos	domum	domus
Ablative	domo	---	domu	domibus

Practice Activity