Lesson 12. Practice with the Third Declension

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We now turn to practice with Third Declension nouns, so that the forms we have learned become steady and ready for use. The purpose of this lesson is not to multiply explanations, but to strengthen memory and to make the patterns familiar through repeated, careful work. If we keep our attention on what is actually assigned, and do not add extra burdens, the Third Declension will become manageable in the same way the earlier declensions became manageable: by steady practice.

It helps to begin by recalling the two principles that govern everything we do with nouns. First, a declension is the variation of a noun by cases. We have already watched this happen in noun after noun: the same word changes form because it is being used differently in speech. Second, the declension of a noun is known by its Genitive singular ending. The First Declension is recognized by a Genitive singular ending in -ae, or -es when the Nominative ends in -e. The Second Declension is recognized by a Genitive singular ending in -i. The Third Declension is recognized by a Genitive singular ending in -is. If we keep that last sign clear—Genitive singular in -is—we will not be thrown off by the many different Nominative endings in the Third Declension.

Because the Third Declension is so large, it is important to realize that we are not learning hundreds of separate things. We are learning a few patterns that apply to many nouns. The nouns we have already learned as examples give us the forms we need for countless other nouns. The most important thing to remember is that endings are added to the stem, and the stem is found by removing the Genitive singular ending. Once we know the Nominative and Genitive singular forms of a noun, we can identify its declension, discover its stem, and decline it.

To see how this works, we can look at several Third Declension nouns that follow the same patterns as the example nouns we already know. A masculine noun like sermo, sermonis shows us the ordinary masculine and feminine pattern with an Accusative singular in -em and an Ablative singular in -e, and with -es in the plural Nominative and Accusative, and -ibus in the plural Dative and Ablative. A neuter noun like tempus, temporis shows us the neuter pattern, where the Nominative, Accusative, and Vocative are always the same, and where the plural Nominative, Accusative, and Vocative end in -a. A common-of-two noun like civis, civis shows us the pattern of nouns that can be masculine or feminine without changing their forms, and it also introduces a Genitive plural that ends in -ium, which we must simply learn by use as we meet such nouns.

With those patterns in mind, we can practice with additional nouns that behave in the same ways. A noun like lapis, lapidis behaves like sermo in its endings. A noun like nomen, nominis behaves like tempus in its neuter behavior. If we practice them side by side, we strengthen our memory of the endings, and we also strengthen the habit of forming the stem from the Genitive.

We begin, then, by declining a masculine noun that follows the same pattern as sermo. We take hic sermo, sermonis, and we keep its stem before our eyes: the Genitive is sermonis, and when we remove -is, the stem is sermon-. In the singular we say hic sermo as the subject, sermonis for “of a speech,” sermoni for “to a speech,” sermonem as the direct object, O sermo in direct address, and a sermone for “from a speech.” In the plural we say sermones as the subject, sermonum for “of speeches,” sermonibus for “to speeches,” sermones as the direct object, O sermones in direct address, and a sermonibus for “from speeches.” When we say these aloud and write them often, we learn not only the endings but also the rhythm of the declension.

Next we practice a noun of the same general masculine pattern but with a different stem and Nominative shape: hic lapis, lapidis. Here we see clearly why the stem must be learned from the Genitive, not guessed from the Nominative. The Genitive is lapidis, and the stem is lapid-. In the singular we say hic lapis, lapidis, lapidi, lapidem, O lapis, a lapide. In the plural we say lapides, lapidum, lapidibus, lapides, O lapides, a lapidibus. The endings are the same as the sermo pattern; only the stem differs. This is exactly what we want to feel: that the declension is stable, and the noun simply supplies the stem.

Now we turn to the neuter pattern, where we must keep one rule especially fixed: in neuter nouns the Nominative, Accusative, and Vocative are always the same in each number. We practice hoc tempus, temporis, whose stem is learned from the Genitive temporis by removing -is, giving tempor-. In the singular we say hoc tempus, temporis, tempori, tempus, O tempus, a tempore. In the plural we say tempora, temporum, temporibus, tempora, O tempora, a temporibus. Here the neuter character is unmistakable: tempus remains unchanged across those three cases in the singular, and tempora remains unchanged across those three cases in the plural.

Alongside this we practice another neuter noun of the same kind: hoc nomen, nominis, whose stem is learned from the Genitive nominis, giving nomin-. In the singular we say hoc nomen, nominis, nomini, nomen, O nomen, a nomine. In the plural we say nomina, nominum, nominibus, nomina, O nomina, a nominibus. Once again, the neuter rule keeps our forms secure, and repeated practice makes the plural in -a feel natural rather than strange.

When we are comfortable with substantive nouns in the Third Declension, we then practice agreement with adjectives, because real reading and composition continually require this. We remember the governing principle: an adjective must agree with its substantive in gender, number, and case. Third Declension adjectives are especially important because they frequently accompany Third Declension nouns, and the forms can look unfamiliar at first.

A helpful example is the adjective felix, felicis, meaning “happy,” used with the noun homo, hominis, meaning “man.” Both are Third Declension forms, and therefore they move together in a way that is consistent, even though the endings are not identical in every case. In the singular we say homo felix for “a happy man” as subject, hominis felicis for “of a happy man,” homini felici for “to a happy man,” hominem felicem for “a happy man” as direct object, O homo felix in direct address, and a homine felice for “from a happy man.” In the plural we say homines felices for “happy men” as subject, hominum felicium for “of happy men,” hominibus felicibus for “to happy men,” homines felices for “happy men” as direct object, O homines felices in direct address, and a hominibus felicibus for “from happy men.” As we practice this, we are not merely memorizing isolated forms. We are training ourselves to make noun and adjective move together automatically in correct agreement.

We also remember that adjectives can sometimes be used without an expressed substantive, because the substantive is understood. This is common in both Latin and English. We may say plainly that Jesus came and saw homines felices, meaning “happy men,” but we may also simply say felices, meaning “the happy (men),” with the noun understood. This habit will appear often in reading, and it is important that we become comfortable with it.

Finally, we keep one more practical note in mind as we practice. In the Third Declension, some Genitive plural forms end in -um, and some end in -ium. We have already seen both kinds. We should not be troubled by this, and we should not try to force every noun into an over-complicated system. The sure path is steady experience in reading and practice in declining. As we meet nouns again and again, the correct plural Genitives will become familiar, and our memory will settle.

This lesson, then, is a lesson of strengthening. We identify Third Declension nouns by the Genitive singular ending in -is. We form stems from the Genitive by removing that ending. We decline masculine and feminine nouns with their characteristic -em in the Accusative singular and -ibus in the plural Dative and Ablative. We decline neuter nouns while keeping the neuter rule fixed, and we practice adjective agreement so that our knowledge becomes usable in real Latin, not merely recited in isolation.

Memory Work

1. How many different terminations are found in the Nominative case of the Third Declension?
Eleven: -a, -e, -o | -c, -d, -l | -n, -r, -s, -t, -x.

2. Decline the Third Declension masculine noun hic Sermo. (State the case name, the Latin form and the English.)
Singulariter: Nominativo, hic Sermo, a speech; Genitivo, Sermonis, of a Speech; Dativo, Sermoni, to a Speech; Accusativo, Sermonem, a Speech; Vocativo, O Sermo, O Speech; Ablativo, a Sermone, from a Speech. Pluraliter: Nominativo, Sermones, Speeches; Genitivo, Sermonum, of Speeches; Dativo, Sermonibus, to Speeches; Accusativo, Sermones, Speeches; Vocativo, O Sermones, O Speeches; Ablativo, a Sermonibus, from Speeches.

In short: Sermo, Sermonis, Sermoni | Sermonem, O Sermo, a Sermone | Sermones, Sermonum, Sermonibus | Sermones, O Sermones, a Sermonibus.

3. Decline the Third Declension feminine noun haec Sedes (Seat). (State the case name, the Latin form and the English.)
Singulariter: Nominativo, haec Sedes, a Seat; Genitivo, Sedis, of a Seat; Dativo, Sedi, to a Seat; Accusativo, Sedem, a Seat; Vocativo, O Sedes, O Seat; Ablativo, a Sede, from a Seat. Pluraliter: Nominativo, Sedes, Seats; Genitivo, Sedium, of Seats; Dativo, Sedibus, to Seats; Accusativo, Sedes, Seats; Vocativo, O Sedes, O Seats; Ablativo, a Sedibus, from Seats.

In short: Sedes, Sedis, Sedi | Sedem, O Sedes, a Sede | Sedes, Sedium, Sedibus | Sedes, O Sedes, a Sedibus.

4. Decline the Third Declension neuter noun hoc Tempus (Time). (State the case name, the Latin form and the English.)
Singulariter: Nominativo, hoc Tempus, Time; Genitivo, Temporis, of Time; Dativo, Tempori, to Time; Accusativo, Tempus, Time; Vocativo, O Tempus, O Time; Ablativo, a Tempore, from Time. Pluraliter: Nominativo, Tempora, Times; Genitivo, Temporum, of Times; Dativo, Temporibus, to Times; Accusativo, Tempora, Times; Vocativo, O Tempora, O Times; Ablativo, a Temporibus, from Times.

In short: Tempus, Temporis, Tempori | Tempus, O Tempus, a Tempore | Tempora, Temporum, Temporibus | Tempora, O Tempora, a Temporibus.

5. What special rule applies to Neuter nouns of the Third Declension?
Neuter nouns of the Third Declension have the Accusative and Vocative the same as the Nominative in each Number.

6. Decline the Third Declension common-of-two noun hic et haec Civis (Citizen). (State the case name, the Latin form and the English.)
Singulariter: Nominativo, hic et haec Civis, Citizen; Genitivo, Civis, of a Citizen; Dativo, Civi, to a Citizen; Accusativo, Civem, a Citizen; Vocativo, O Civis, O Citizen; Ablativo, a Cive, from a Citizen. Pluraliter: Nominativo, Cives, Citizens; Genitivo, Civium, of Citizens; Dativo, Civibus, to Citizens; Accusativo, Cives, Citizens; Vocativo, O Cives, O Citizens; Ablativo, a Civibus, from Citizens.

In short: Civis, Civis, Civi | Civem, O Civis, a Cive | Cives, Civium, Civibus | Cives, O Cives, a Civibus.

7. Summary of the Third Declension:

Note to Parent/Praeceptor: See that the Genitive plural termination is sometimes -um and sometimes -ium, depending on the word. Modern efforts to multiply rules and systematize the Third Declension should be ignored. Experience is the only means to mastery.

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