The second declension
dominus and pīlum: masculine -us nouns and neuter -um nouns.
LatinBeginning Latin · The second declensionAbout 4 min: 1 reading, 3 practiceUpdated
- Decline a second-declension noun in -us and in -um
- Use the genitive singular to tell which declension a noun belongs to
- Remember that -um nouns are neuter and their plural ends in -a
Latin Level 1: nouns and cases: lesson 6 of 13
- Beginning Latin · Sounds
- Saying Latin out loud 4 min
- Beginning Latin · How sentences work
- Endings do the work 3 min
- The five cases 3 min
- Beginning Latin · Nouns
- The first declension 3 min
- Adjectives agree with their nouns 3 min
- Beginning Latin · The second declension
- The second declension 4 min
- Predicate nouns and apposition 3 min
- Adjectives in all three genders 3 min
- Nouns in -ius, -er and -ir 4 min
- Beginning Latin · Pronouns and adjectives
- My, your, his, our 3 min
- Beginning Latin · The ablative
- Four ways to say "with" 3 min
- Beginning Latin · Pronouns and adjectives
- The nine irregular adjectives 4 min
- is, ea, id: this, that, he, she, it 3 min
Try first
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Pairs with D'Ooge, Latin for Beginners (Ginn, 1909), Lesson IX ("The Second or O-Declension"), §§ 70–74
What it is
Nouns whose genitive singular ends in -ī belong to the second declension. Most end in -us and are masculine, like dominus (master); those in -um are neuter, like pīlum (spear).
Text description
dominus, form by form: Nom. sg. dominus (ending -us); Gen. sg. dominī (ending -ī); Dat. sg. dominō (ending -ō); Acc. sg. dominum (ending -um); Abl. sg. dominō (ending -ō); Nom. pl. dominī (ending -ī); Gen. pl. dominōrum (ending -ōrum); Dat. pl. dominīs (ending -īs); Acc. pl. dominōs (ending -ōs); Abl. pl. dominīs (ending -īs).
Neuter pīlum follows the same pattern except in three places: nominative singular pīlum, and nominative and accusative plural pīla.
Quick check
Tap an answer to check it.
Which declension is equus, equī (horse)?
- First-declension genitives end in -ae
Show answer
Second. A genitive singular in -ī means the second declension.
Why it matters
From now on, a dictionary gives each noun as nominative, genitive and gender: dominus, -ī, m. The genitive tells you which set of endings to use, so it is worth learning with every noun.
Worked example
- Servus dominum vocat. → The slave calls the master.
- Dominī equōs cūrant. → The masters care for the horses. (dominī nominative plural, equōs accusative plural)
- Oppida sunt magna. → The towns are large. (neuter plural in -a)
Calling someone uses the vocative. For -us nouns it ends in -e: Domine! (O master!), Serve! (O slave!).
Common mistake
Giving a neuter plural the ending -ī: wrong: pīlī for "spears" as a subject or object. Neuter nouns end in -a in the nominative and accusative plural: pīla, oppida, bella.
More detail: three rules for every declension
The nominative, accusative and vocative of a neuter noun are always alike. The dative and ablative plural are always alike. Apart from -us nouns like dominus, the vocative is like the nominative (D'Ooge § 74).
Key terms
- second declension
- nouns with genitive singular in -ī
- neuter
- neither masculine nor feminine; nouns in -um
- vocative
- the case for calling someone: Domine!
- dominus, -ī, m.
- master
- pīlum, -ī, n.
- spear
Practise the key terms
Tap a card to turn it over. 5 cards.
| Front | Back |
|---|---|
| second declension | nouns with genitive singular in -ī |
| neuter | neither masculine nor feminine; nouns in -um |
| vocative | the case for calling someone: Domine! |
| dominus, -ī, m. | master |
| pīlum, -ī, n. | spear |
Practice
Recognition drill
Pick the right answer, as fast as you can.
All pairs
Tap a card to turn it over. 6 cards.
| Front | Back |
|---|---|
| dominī | genitive singular or nominative plural |
| dominō | dative or ablative singular |
| dominum | accusative singular |
| dominōrum | genitive plural |
| dominōs | accusative plural |
| domine | vocative singular |
Quick quiz
Tap an answer to check it.
What is the genitive plural of equus?
- That is dative or ablative plural
- That is genitive singular or nominative plural
Show answer
equōrum. Second-declension genitive plural ends in -ōrum.
"The wars" as a subject, from bellum, -ī, n.
- Used the masculine ending; bellum is neuter
Show answer
bella. Neuter plural nominative ends in -a.
How do you call out "O slave!" to servus?
- The vocative of -us nouns ends in -e
Show answer
serve. Vocative of -us nouns: -e.
Practise speaking
Studyfern has no voice tools of its own. To practise out loud, copy this prompt into a voice-capable AI assistant and talk with it.
You are a patient Latin tutor. Use the classical pronunciation only, never the Church one: c is always k, g is always hard, v sounds like w, ae like the ai in aisle, and long vowels are held longer. Speak slowly. Use only these Latin words: dominus, pīlum, servus, oppidum, bonus. Ask me to decline dominus and pīlum aloud, all cases, singular and plural, including the vocative of dominus. Then ask me single forms. Do 8 single forms after the full declensions. After each answer, tell me what kind of mistake I made, if any, and let me try again, then tell me one thing to improve. Keep every reply under 2 sentences. If I need a name or a town, I will make one up. Speak English except for the Latin itself.
Listen too. Listen to native speakers before and after: see the free listening and shadowing links.
Good to know. AI feedback on pronunciation is hit and miss, so check yourself against native recordings. This course teaches the classical pronunciation (see lesson 1); AI voices may mix it with the Church (Italian-style) one, so ask for classical and check against lesson 1. Don't share personal details: use a made-up name and town.
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In short
- Second declension: genitive singular -ī.
- -us nouns are mostly masculine; -um nouns are neuter.
- dominus: -us, -ī, -ō, -um, -ō; plural -ī, -ōrum, -īs, -ōs, -īs.
- Neuter: nominative and accusative plural in -a (pīla).
- Vocative of -us nouns ends in -e (domine).
Mastery check
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Check yourself
Answer in your head first, then open the answer. Nothing is saved.
What is the accusative plural of mūrus (wall)?
Show answer
mūrōs.
What is the nominative plural of oppidum (town)?
Show answer
oppida.
How do you know lēgātus, -ī is second declension?
Show answer
Its genitive singular ends in -ī.
Further reading
- D'Ooge, Latin for Beginners, Lesson IX, §§ 70–74. Public domain; Project Gutenberg.
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