1. 3rd Declension Nouns (Lesson 40)
Latin I
Feb , 2014

2. Third Declension Nouns!
Latin has 5 declensions of nouns.
Declensions are groups of nouns which share the same endings.

3. 3rd declension nouns
Third declension is the largest declension of nouns!
Third declension includes masculine, feminine, and neuter nouns, plus a sub-group called “i-stem nouns.”
Both masculine and feminine 3rd declension nouns use the same chart.

4. -is 3rd declension nouns Third declension nouns are identified by the
–is ending in the genitive singular.
pax, pacis (f.)
lex, legis (f.)
salus, salutis (f.)
dux, ducis (m.)
-is

5. 3rd Declension Endings --- -ēs -is -um -i -ibus -em -ēs -e -ibus
Singular Plural
Nominative*
Genitive
Dative
Accusative
Ablative
---
-ēs
-is
-um -i
-ibus
-em
-ēs -e
-ibus
* There are several nominative endings, so they’re not
listed on the chart. Whatever the first form of the word is
in your vocabulary list…that’s the nominative.

6. Has a different spelling
Step 1 – Find the noun stem
The noun stem is found by dropping the genitive singular ending from the noun.
Dictionary entry of a noun:
pax, pacis, f peace
Often the stem
Has a different spelling
Than the nominative!
Nominative singular
Gender
Meaning
Genitive singular
pacis – is = pac
Noun Stem

7. Let’s Find Stems for 3rd Declension!
dux, ducis
homo, hominis
lex, legis
miles, militis
pax, pacis
salus, salutis
duc-
homin-
leg-
milit-
pac-
salut-

8. Step 2: Add the case endings to the noun stem.
Singular Plural
Nominative
Genitive
Dative
Accusative
Ablative
dux
duc
Note that the
lovely nominative form will appear once on the chart, then disappear…like a briefly-lived bug. 
duc
duc
duc
duc
duc
duc
duc
duc
ibus
ibus
dux, ducis (m.) e es is em es i um

9. Your Turn!
Decline any 1 of your third declension vocabulary nouns on the whiteboard.

10. Nouns and Adjectives
The adjectives you have learned thus far are called “1st/2nd declension adjectives”
bonus, bona, bonum
Therefore, they do not use 3rd declension endings!

11. bonus, bona, bonum Nom. bonus boni Gen. boni bonorum Dat. bono bonis
Acc bonum bonos
Abl bono bonis
Masculine forms use 2nd declension endings.
Nom bona bonae
Gen bonae bonarum
Dat bonae bonis
Acc bonam bonas
Abl bonā bonis
Feminine forms use 1st declension endings.
Nom bonum bona
Gen boni bonorum
Dat bono bonis
Acc bonum bona
Abl bono bonis
Neuter forms use 2nd declension neuter endings.

12. Nouns and Adjectives
But what if you need to use a 1st/2nd declension adjective to describe a 3rd declension noun?!?!

13. Nouns and Adjectives Remember our old abbreviation G-N-C?
Nouns and adjectives agree in gender, number, and case.
They DO NOT have to agree in declension!
This means: often nouns and adjectives have endings that AGREE but AREN’T SPELLED the same way.

14. Nouns and Adjectives
Let’s say we want to decline the pair of words “a good law.”
lex, legis (f.)---law
bonus, BONA, bonum---good
So, a good law is a “lex bona”
Let’s see what it looks like…

15. Lex Bona
Singular
Plural
Nom. lex bona leges bonae Gen. legis bonae legum bonarum Dat. legi bonae legibus bonis Acc. legem bonam leges bonas Abl. lege bonā legibus bonis

16. Your Turn! Decline “arbor magna” on a single chart on the whiteboard.
Decline “dux bonus” on a single chart on the whiteboard. “Dux” is masculine so “bonus” is masculine---use 2nd declension endings on “bonus.”

17. 3rd Declension Practice! Worksheet Answers
ducem: acc. sg.
militis: gen. sg.
regum: gen. pl.
matribus: dat./abl. pl.
arbores: nom./acc. pl.
patri: dat. sg.
lege: abl. pl.
1. B
2. A
3. B
4. C
5. C
6. A, B

18. 3rd Declension Practice! Worksheet Answers
Nominative
Genitive
Dative
Accusative
Ablative
1. B
2. A
3. B
4. C
5. C
6. A, B

19. 3rd Declension Practice! Worksheet Answers
Equi militum sunt magni. Equi: nom. pl. subject Militum: gen. pl. “of”
The horses of the soldiers are big.

20. 3rd Declension Practice! Worksheet Answers
Rex reginam amat. Rex: nom. sg., subject Reginam: acc. sg., direct object
The king loves the queen.

21. 3rd Declension Practice! Worksheet Answers
Pater agricolas docebit. Pater: nom. Sg., subject Agricolas: acc. Pl., direct object
Father will teach the farmers.

22. 3rd Declension Practice! Worksheet Answers
Equus ducis puellam terret. Equus: nom. Sg., subject Ducis: gen. sg., “of” Puellam: acc. Sg., direct object
The horse of the leader frightens the girl.

23. 3rd Declension Practice! Worksheet Answers
Milites gladiis nautas pugnabunt. Milites: nom. Pl., subject Gladiis: abl. Pl., “by means of” Nautas: acc. Pl., direct object
The soldiers will fight the sailors by means of swords (with swords).

24. 3rd Declension Practice! Worksheet Answers
Puellae arbores magnas amant. Puellae: nom. Pl., subject Arbores: acc. Pl., direct object
The girls like/love the big trees.

25. 3rd Declension Practice! Worksheet Answers
Regina fratribus pecuniam donabat. Regina: nom. Sg., subject Fratribus: dat. Pl, indirect object “to/for” Pecuniam: acc. Sg., direct object
The queen gave/was giving money to the brothers.

26. 3rd Declension Practice! Worksheet Answers
Agricola militibus viam longam monstrat. Agricola: nom. Sg., subject Militibus: dat. Pl., indirect object “to/for” Viam: acc. Sg., direct object
The farmer shows the long road to the soldiers.

27. 3rd Declension Practice! Worksheet Answers
Cibus agricolae regem non servabit. Cibus: nom., sg., subject Agricolae: gen. sg., “of” Regem: acc. Sg., direct object.
The food of the farmer will not save the king.

28. 3rd Declension Practice! Worksheet Answers
Dux regi victoriam militum nuntiat. Dux: nom. Sg., subject Regi: dat. Sg., indirect object “to/for” Victoriam: acc., sg., direct object Militum: gen. pl., “of”
The leader announces the victory of the soldiers to the king.