In the eleventh class of the Latin from Scratch course, we’ll study the third declension, the most complex but probably the most prolific. That’s why it is so important to master it already. Also, what we’re about to learn now will be necessary for the 3rd declension adjectives.
I explain everything in the following video ():
Morphology of the third declension
The third declension is divided into two big groups. We can quickly classify a 3rd declension noun by looking at the statement:
- consonant-stem: nouns with a different amount of syllables between the nominative and the genitive (e.g. mi‑les, mi‑li‑tis)
- i-stem: nouns with the same amount of syllables (e.g. ci‑vis, ci‑vis)
However, there are exceptions where the rules are the opposite:
- consonant-stem (but look like i-stem): mater, matris; frater, fratris; pater, patris
- i-stem (but look like consonant-stem): nouns whose nominative singular ends in 2 or more consonants and whose genitive singular has 2 consonants right before ‑is (e.g. mons, montis; urbs, urbis; pars, partis)
The distinction between these two groups is relatively important, since there are some different endings.
Masculine and feminine nouns are declined the same, whereas neuter nouns have some already known particularities.
Precisely because of these particularities, it is important to quickly identify neuter nouns, which meet one of the following criteria:
- nominative singular in ‑men (e.g. carmen, carminis; flumen, fluminis)
- nominative singular in ‑us and genitive singular in ‑eris, ‑oris or ‑uris (e.g. vulnus, vulneris; corpus, corporis; ius, iuris); not to be confused with 2nd or 4th declension nouns, which can also end in ‑us!
- dental-stem (d, t) with a nominative not ending in ‑s (e.g. caput, capitis; cor, cordis; lac, lactis)
In the following four tables, you have to take into account that the nominative and vocative (and accusative neuter) singular do not have an ending of their own; instead, each specific word has its own ending for those cases.
|nom. sg.||homo||nom. pl.||hominēs|
|voc. sg.||homo||voc. pl.||hominēs|
|ac. sg.||hominĕm||ac. pl.||hominēs|
|gen. sg.||hominĭs||gen. pl.||hominŭm|
|dat. sg.||hominī||dat. pl.||hominĭbus|
|ab. sg.||hominĕ||ab. pl.||hominĭbus|
|nom. sg.||caput||nom. pl.||capită|
|voc. sg.||caput||voc. pl.||capită|
|ac. sg.||caput||ac. pl.||capită|
|gen. sg.||capitĭs||gen. pl.||capitŭm|
|dat. sg.||capitī||dat. pl.||capitĭbus|
|ab. sg.||capitĕ||ab. pl.||capitĭbus|
The i-stem declension is not so common in nouns, but it is widely used in adjectives.
Also this group has masculine-feminine and neuter paradigms. To find out what nouns are neuter, we should look at the nominative singular: they end in ‑e (e.g. mare, maris; rete, retis). However, many of them have lost this ‑e, which makes them look like consonant-stem; we know they are i-stem because the nominative ends in ‑al or ‑ar, as long as they don’t refer to persons (e.g. animal, animalis; vectigal, vectigalis; exemplar, exemplaris).
|nom. sg.||hostis||nom. pl.||hostēs|
|voc. sg.||hostis||voc. pl.||hostēs|
|ac. sg.||hostĕm||ac. pl.||hostēs (-is)|
|gen. sg.||hostĭs||gen. pl.||hostiŭm|
|dat. sg.||hostī||dat. pl.||hostĭbus|
|ab. sg.||hostĕ||ab. pl.||hostĭbus|
The accusative plural is most often ‑ēs, but it can appear as ‑is.
|nom. sg.||mare||nom. pl.||mariă|
|voc. sg.||mare||voc. pl.||mariă|
|ac. sg.||mare||ac. pl.||mariă|
|gen. sg.||marĭs||gen. pl.||mariŭm|
|dat. sg.||marī||dat. pl.||marĭbus|
|ab. sg.||marĭ||ab. pl.||marĭbus|
That’s most of the theory we need to know about the third declension. Now let’s learn its adjectives.