Latin/3rd Declension Lesson 1

Salvēte!

This is the latest in the series of Latin lessons. For a guide to previous lessons and a classified vocabulary list, be sure to check out these links on the right.

New Grammar
This is going to be a bit involved – if you just want to jump to the sentences and save grammar study for later, go ahead and scroll down.

Latin nouns are classified into 5 different groups, known as declensions. If you’ve followed this far, we’ve covered the first and second declensions of nouns (and some adjectives). Learning the sets of case endings within each declension is essential to being able to use nouns accurately in Latin sentences. There are five cases in general use for each declension. This week, we’ll start the process of mastering the 3rd declension. Bear with me this lesson, because the 3rd declension is fairly complex and there are several rules that need to be laid out. Don’t be surprised if it takes several repeats through the vocabulary and sentences to understand some of these concepts.

3rd declension nouns are classified by their genitive singular, which ends in -is. The gen. s. also gives the stem of the noun, and there is sometimes considerable variation between the nominative and the genitive. For example,
 * homō, hominis = man.

The stem is homin- and all other forms will follow the form of the stem, not the nominative. Nominatives have no regular ending in the 3rd declension: the --- in the case table basically means “anything goes.”

Gender rules … actually, more like guidelines. All 3 genders occur in the 3rd declension. There is one set of endings that works for masculine or feminine nouns, and one set for neuter nouns. The differences in gender endings occur in the nominative and accusative forms; all other forms are identical regardless of gender. The first rule and the only one without exceptions is called the “natural gender” rule. Nouns naming male or female persons always are the gender of the person named.
 * Soror, sororis (f.) = sister” or frater, fratris (m.) = brother.

Some nouns that can be either masculine or feminine are listed as “common” gender:
 * canis, canis (c.) = dog or hostis, hostis (c.) = enemy.

Most of these nouns are assumed to be masculine unless you have a specific sign otherwise like a feminine modifier (e.g. parvae canēs = the small female dogs).

Then, to make an educated guess about the gender of other 3rd declension nouns, I suggest the “SOX, ERROR and LANCET” rules.

Look at the final letter of the nom. s.
 * If it is S, O, or X the gender is usually feminine (because the women have to pick up all the SOX);
 * if it is ER, R, or OR it is usually masculine (because, you guessed it, men make all the mistakes); and
 * if it is L,A,N,C,E, or T it is usually neuter, because a lancet is just a thing (neither masc. nor fem.) that doctors use.

These “rules” have plenty of exceptions, but cover most of the 3rd declension nouns that aren’t already covered by the Natural Gender Rule. Oh yes, there are also quite a few neuter nouns than end in –us in the nom. s. and –ris in the gen. s. Because it’s all so confusing, we’ll list the gender in the vocabulary listings as well.

I-stems
Some 3rd declension nouns have an extra -i- added before the gen. pl. ending. These will be listed in the vocabulary this way:
 * pars, partis, partium (f.) = part.

Since we aren’t going into the genitives other than to identify the stem this lesson, we’ll save the gory details for a future lesson! We’ll just have an assortment of regular nouns of all 3 genders this week.

We will focus on the nominatives and accusatives this lesson. Remember, nominative is for subject or predicate nouns, and accusative is for direct objects. Study the highlighted sections of the case table below for these, and note the differences between m./f. and n. Let’s take pater, patris as our example for m/f nouns, and flūmen, flūminis as an example for neuter.


 * Nom. s. = pater; acc. s. = patrem. Nom. pl. and acc. pl. both = patrēs.

Remember that for neuter nouns, nom. and acc. are the same. So:
 * Nom. and acc. s. = flūmen. Nom. and acc. pl. = flūmina.

The spelling change that occurs in the genitive s. applies to all other cases except nom. s. for m./f. nouns, and to all cases except nom. and acc. s. for neuter nouns.

Practice
Well, this has been a long and complex lesson, and we hope it hasn’t been too overwhelming. Sorting out the 3rd declension nouns is challenging, but the remaining two declensions will be easy by comparison. You can also check the classified vocabulary list, where you can study 3rd declension nouns classified by a) m./f. regular, b) n. regular, c) m./f. i-stem, and d) n. i-stem. You may find it helpful to study the groups of nouns together in this way. Excelsior! (Ever higher!)