Partitive Genitive
The partitive genitive marks the whole that some part belongs to: pars mīlitum — "part of the soldiers," quis nostrum — "who of us?" The English "of" is the giveaway, but Latin only reaches for the genitive when the head word is genuinely partitive: a number, a quantity word, a comparative or superlative, an indefinite pronoun, or a neuter substantive like quid novī ("what news?").
The trap is that Latin doesn't always agree with English about whether something IS partitive. Cardinal numerals (except mīlia) and quīdam prefer the ablative with ex or dē — Caesar writes paucī dē nostrīs, not paucī nostrōrum.
And when the meaning is the whole class ("all of us," "many soldiers") rather than a part, Latin uses agreement: nōs omnēs, multī mīlitēs — never omnēs nostrum, multī mīlitum.
Learnings0 core · 1 AP claim
AP framework claims (1)— verbatim from AP CED
"some / one / part / how much OF the larger group" — the genitive names the pool you're pulling from.
Cardinal numerals (except mīlia) and quīdam prefer ex/dē + ablative: ūnus ex eīs, not ūnus eōrum.
See It In Action
— Cic. Cat. i. 1
Two partitives in one breath — quid cōnsilī ("what of plan") and quem nostrum ("which of us"). Both head words are pronouns, the canonical trigger for the partitive.
— B. G. iv. 1
Superlatives are partitive magnets: māxima ... Germānōrum omnium picks the Suebi out of the German pool. The whole sits in the genitive; the superlative does the picking.
— B. G. ii. 23
Pars is THE prototype partitive noun. Notice the participle impedītam agrees with partem (the part), not with eōrum (the whole) — modifiers track the head, not the genitive.
— B. G. iv. 32
aliquid novī is the textbook neuter-substantive partitive — "something OF new." Then cōnsilī nests under novī as a second partitive: "something of new (kind) of plan." Latin packs the chain tighter than English ever does.
For "one of the soldiers," Latin offers two routes — but cardinal numerals usually pick the ablative.
default for pronouns, comparatives, superlatives, partitive nouns
ūnus tribūnōrum
one of the tribunes
default for cardinal numerals (except mīlia) and quīdam
ūnus ex tribūnīs
one of the tribunes
Tip: Ask: is the head word a cardinal numeral or quīdam? If yes, expect ex/dē + ablative. If it's a pronoun, comparative, or superlative, expect the genitive. Both forms are grammatical; preference is what's at stake.
In Caesar's aliquid novī cōnsilī (B. G. iv. 32), what case are novī and cōnsilī, and why?
Study Tips
- •Memorize the trigger list: numbers, partitive nouns (pars, numerus), pronouns (quis, nēmō, aliquid), comparatives, superlatives, neuter substantives. If the head word isn't on that list, the genitive probably isn't partitive.
- •When you see ūnus, duo, trēs, or any cardinal except mīlia, expect ex/dē + ablative — ūnus ex eīs, not ūnus eōrum. Both are legal but Caesar's default is the ablative.
- •Treat omnēs, multī, paucī as adjectives in English-style agreement: nōs omnēs, multī cīvēs. The partitive genitive only fires when you're picking SOME out of a larger pool.