3rd declension noun gen pl ending in -ium/-um

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3rd declension noun gen pl ending in -ium/-um

Post by Sofronios » Fri Jun 15, 2018 3:03 am

still struggling with my basic latin
this question came to mind when I am trying to complete a Latin sentence, and in the near immediate future I think I will be doing Latin composition.
how do we differentiate 3rd decelnsion noun with genitive plural ending in just -um or in -ium?
The text (Orberg grammatica latina) simply tells that ovis, navis, urbs, et alia multa, end their genitive plural in -ium, while the rest out of this particular group seems to end in -um.
is there any hint that we can use to see which noun belong to which group?
thx in advance
ὁ δὲ εἶπε· πῶς γὰρ ἂν δυναίμην, ἐὰν μή τις ὁδηγήσῃ με;
Qui ait : Et quomodo possum, si non aliquis ostenderit mihi ?

Barry Hofstetter
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Re: 3rd declension noun gen pl ending in -ium/-um

Post by Barry Hofstetter » Fri Jun 15, 2018 3:41 am

The rules to distinguish i-stem third declension nouns from regular third declension nouns. I-stems are what we call the the third declension nouns whose genitive plural is -ium.

1. Nouns which end in -is or -es and have the same number of syllables in the genitive singular, e.g., hostis, hostis, m.

An exception is canis, canis, m/f, which has a regular third declension genitive plural, canum.

2. Nouns ending in -ns or -rs in the nominative singular, e.g., mons, montis, m.

3. Nouns of one syllable in the nominative singular whose base ends in two consonants, nox, noctis, f.

Neuter i-stems are rare, ending -al or -e, e.g, animal, animalis, n. or mare, maris, n. Notice that in addition to the genitive plural -ium, these have ablative singular in -ī.
N.E. Barry Hofstetter
The Jack M. Barrack Hebrew Academy
καὶ σὺ τὸ σὸν ποιήσεις κἀγὼ τὸ ἐμόν. ἆρον τὸ σὸν καὶ ὕπαγε.

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