Lesson 9 · Review

The Second Declension: O-Stem Nouns — vocabulary, rules, and a self-check

IVocabulary

Thirteen new nouns and two new verbs. Most nouns belong to the new second declension — masculine in -us, neuter in -um; cōnstantia is a first-declension feminine. Say each aloud; the English derivatives in parentheses help fix the meaning.

bellumwar (re-bel)
cōnstantiafirmness, constancy
dominusmaster, lord (dominate)
equushorse (equine)
frūmentumgrain
lēgātuslieutenant, ambassador (legate)
MārcusMarcus, Mark
mūruswall (mural)
oppidānustownsman
oppidumtown
pīlumspear (pile driver)
servusslave, servant
SextusSextus
cūratcares for (+ acc.)
properathastens

IIThe Second Declension: O-Stem Nouns

How the genitive singular fixes a noun's declension, why -um nouns are neuter and -us nouns masculine, the one vocative that breaks the rule, and how a predicate noun takes its case from the subject. Two models carry the paradigm: dominus, "master," and pīlum, "spear."

Rule 1 — The genitive singular names the declension

Latin has five declensions, and a noun's declension is shown by the ending of its genitive singular — not its nominative. So always learn a noun's genitive (and its gender) alongside the nominative. The second declension's genitive singular ends in .

dominus, dominī, m. (gen. -ī → 2nd decl.); domina, dominae, f. (gen. -ae → 1st decl.).

Rule 2 — The second (O-) declension: -us and -um

The nominative singular of an O-declension noun ends in -us (or -er, -ir) or in -um; the genitive singular ends in . The base is found by dropping that : dominīdomin-, pīlīpīl-.

Singular: dominus · dominī · dominō · dominum · dominō (voc. domine). Plural: dominī · dominōrum · dominīs · dominōs · dominīs.

Rule 3 — Gender by ending, and the neuter rule

Nouns in -um are neuter; the others are regularly masculine. For every neuter noun the nominative and accusative are alike, and in the plural they end in -a.

pīlum (n.): nom.=acc. sg. pīlum; nom.=acc. pl. pīla. So is oppidum → oppida, bellum → bella.

Rule 4 — The one vocative exception

The vocative is normally just like the nominative. The great exception: the vocative singular of an -us noun ends in -e. (Neuters in -um keep the nominative form.)

dominus → domine, "O master"; servus → serve, "O slave"; Mārcus → Mārce, "Marcus!"

Rule 5 — A predicate noun agrees in case with the subject

A noun joined to the subject by the copula (est, sunt) to define it is a predicate noun, and it agrees in case with the subject — so it stands in the nominative, never the accusative, even though English puts it after "is."

Sextus est lēgātus, "Sextus is a lieutenant" — both Sextus and lēgātus are nominative.

IIISelf-check

Six out of six before you start the exercises.

Question 1

What tells you which declension a noun belongs to?

Right. Rule 1 — a noun's declension is shown by the genitive singular ending, which is why you learn the genitive (and gender) with the nominative. The second declension's genitive ends in (dominī, pīlī); the first declension's in -ae (dominae).

Not quite — the nominative alone can mislead. Which form does Rule 1 call the giveaway?

Question 2

A second-declension noun whose nominative singular ends in -um is what gender?

Right. Nouns in -um are neuter (bellum, pīlum, oppidum, frūmentum); those in -us are regularly masculine (Rule 3).

Not quite — look at Rule 3. The ending -um always marks one particular gender.

Question 3

You call out to your master. What is the vocative singular of dominus?

Right. The vocative singular of an -us noun ends in -e: dominusdomine, servusserve, MārcusMārce. This is the one great exception to "the vocative is like the nominative" (Rule 4).

Not quite — calling out to a -us noun changes its ending. Recall the vocative exception in Rule 4.

Question 4

Pīlum ("spear") is neuter. What is its nominative and accusative plural?

Right. In a neuter noun the nominative and accusative are alike, and in the plural they end in -a: pīlumpīla (Rule 3). The forms pīlī and pīlōs belong to masculine -us nouns.

Not quite — pīlum is neuter, and neuter plurals share one special ending. Which one?

Question 5

In Sextus est lēgātus ("Sextus is a lieutenant"), why is lēgātus nominative rather than accusative?

Right. Joined to the subject by est, lēgātus is a predicate noun and agrees in case with the subject (Rule 5). Sextus is nominative, so lēgātus is too — the copula takes no object.

Not quite — est doesn't take an object. What case must a word linked to the subject share? See Rule 5.

Question 6

Which statement about a neuter noun like oppidum is true?

Right. For every neuter noun the nominative and accusative are identical, and in the plural they end in -a: oppidumoppida (Rule 3). The -e vocative and the -us nominative belong only to masculine -us nouns.

Not quite — two of these describe masculine -us nouns. Which one is the neuter rule?

Answered correctly: 0 / 6