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Chapter 7

RULE 1: Third declension nouns have a consonant at the end of the base.

RULE 2: The base of a third-declension noun is determined by dropping -is from the genitive singular. Nominative singulars are irregular for the most part.

I. Grammar

A. The Nature of the Third Declension.

Let's begin by addressing the whole picture of nouns and their declensions in Latin. Latin has five declensions total, grouped according to the type of sound which comes at the end of a noun's base. First declension includes nouns which have bases ending in -a, second declension nouns have bases ending in -o, third in consonants, fourth in -u and fifth in -e. Those bases which ended in -i are represented in Latin as i-stem nouns, a group which Latin grammarians included with third-declension nouns because of their superficial similarity to consonant-base forms (we'll learn i-stem forms later). Linguists have shown that, in fact, the same set of endings were used across all of Latin, but they were changed dramatically under different circumstances. For instance, the Indo-European accusative singular ending -m which the Romans inherited from their forebears manifested in Latin as -am (first declension), -um (second and fourth declensions) and -em (third and fifth declensions), depending on what sort of final vowel it encountered in the noun base, in other words, what declension it belonged to.

The third declension is a catch-all category of all nouns which had consonants at the end of their bases. These consonants predicated certain changes in the inherited endings, creating what looks like a variable set of unique endings because the endings reacted differently to different consonants at the end of noun bases. In other words, case endings sometimes vary even within third declension, especially in the nominative singular forms where the consonant at the end of the noun base ran into the nominative case ending -s (see below, The Nominative Singular in Third Declension). All in all, be forewarned that there is a good deal of memorization necessary here.

But it's not all bad news. The mechanics for producing and analyzing third-declension forms are actually quite simple. Memorize a third-declension noun's nominative singular form (it's often irregular!) and its genitive singular form along with its gender, and all other forms follow naturally from there. From the genitive singular form—not the nominative!—drop -is which will always come at the end of a third-declension noun's genitive singular, and what remains is the base used to form the rest of the word's forms. For example, memorize "rex, regis, masc.," then drop -is from regis, leaving reg- which is the noun base for this word. To reg-, then add the third-declension case endings (see below). The nominative singular rex is irregular and unpredictable; it must be memorized as such.

B. Third Declension Endings

Here are the endings for third declension:

NOMINATIVE (VOCATIVE) masc/fem = *-s (neuter = zero) -es
GENITIVE -is -um
DATIVE -ibus
ACCUSATIVE -em (neuter = zero) -es (archaic -îs)
ABLATIVE -e -ibus
*nominative singular forms are irregular and must be memorized for each word

There are no mandatory long marks in this declension. It's very important not to confuse endings from different declensional systems, e.g.:

-us nominative singular masculine nominative/accusative singular neuter
-î genitive singular masculine/neuter and nominative plural masculine dative singular
-e vocative singular masculine ablative singular
-um nominative singular neuter and accusative singular neuter/masculine genitive plural
-is* dative/ablative plural (long î) genitive singular (short i)

C. The Nominative Singular in Third Declension

The nominative singular forms in third declension must be memorized individually for each word. There are, however, patterns which may assist in that memorization:

Nominative Singulars in Third Declension
End of Base + -s = Nom. Sing. Example
-g/c-  +  -s  =   -x rex, lex, vox, pax, dux, lux
-(n)t/d-  + -s  =   -(n)s, virtus, salus, civitas, potens, laus [This includes the large group of nouns ending: -tû(t)s and -tâ(t)s.]
-on-/-in- (m/f)  + -s  =   -o ratio, Cicero, homo, virgo, multitudo [This includes the large group of nouns ending, -tûdo- and -tio-.]
-in- (neut)  + -s  =  -en nomen, certamen, flamen
-r-  + -s  =   -er pater, mater, frater
-ar-  + -s  =   -ar Caesar, exemplar
-or- (m/f)  + -s  =   -or labor, amor, soror (exception: monosyllables which retain final -s, e.g. mos, flos, ros) [This includes the large group of nouns ending: -or and -tor.]
-or/er- (neut)  + -s  =   -us tempus, corpus, genus, opus, scelus
-it-  + -s  =   -es/ut miles, caput
-ul/ol-  + -s  =   -ul/ol sol, consul

We will not encounter examples of some of these forms until later chapters, e.g. Caesar (Chapter 12), pater (Chapter 15), sol (Chapter 27) and miles (Chapter 29). Nevertheless, it's important to learn as many of these patterns as possible now.

D. The Gender of Third-Declension Nouns

One challenge in learning the third declension is memorizing the gender of nouns, which is much less readily apparent in the majority of third-declension forms than in first and second. In footnote 2 on page 32, Wheelock surveys categories of forms which share a certain gender. This list can be helpful in committing to memory the gender of some third-declension words. It may also facilitate this memorization process to list together third-declension nouns grouped by gender (as is done on the vocabulary sheets for this declension), in that the mere visual association of feminine, masculine or neuter nouns may help you recall a noun's gender.

E. Homework

Decline and translate fully on a separate sheet the following noun/adjective phrases: bonus mos, libera civitas and multum tempus. This is to be turned in for credit.

F. Handout

Click here for a worksheet on third-declension nouns.

II. Vocabulary

[Note carefully what declension each noun in this vocabulary list belongs to.]

homo: Means "human being," with no gender implied (cf. humanity); cf. vir, "a male."

littera: Means a "letter of the alphabet," not a "mailed letter." A "mailed letter" in Latin is an epistula (a word borrowed from Greek) or litterae (a collection of alphabetic letters, as in a bowl of alphabet soup). "Letters," in the sense "literature," is still preserved in English phrases like "Arts and Letters" and "a man of letters."

mos: A mos is fundamentally "a habit," something a person does regularly, like brush his teeth, comb his hair or walk his dog. To the Romans, the plural of this word, literally "(the sum of) one's habits," adds up to and illustrates one's "character," which suggests that the Romans measured the whole of a man by the summation of the many things he did, or in modern lingo, his "little ways." It is certainly true that, if you regularly ignore your children, yell at your servants and hide money in jars, it says something about your general character.

pax: The English word "peace" derives from Latin pax but only after it passed through French, which explains the dramatic change in spelling and pronunciation.

virtus: Literally, "the quality of being (-tus) a man (vir-)," i.e. "manliness."

post: This preposition takes an accusative object.

audeo: This verb takes a complementary infinitive, "dare to . . ."

amor: The abstract noun derived from amo.

sub: This preposition takes both an accusative and an ablative object. With an ablative object, it shows "position at" or "motion from" ("The snake was under the rock but now it's coming out from under the rock."). With an accusative object, it shows "motion toward" ("And now the snake is crawling back under the rock!").


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