1. Lesson XL (40)
3rd declension nouns

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 (we’ll work with the neuter nouns later on).
Both masculine and feminine 3rd declension nouns use the same chart.

4. 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.)

5. Nominative Genitive Dative Accusative Ablative -es -is -um -i -ibus
3rd Declension Endings
Singular Plural
Nominative
Genitive
Dative
Accusative
Ablative
---
-es
-is
-um -i
-ibus
-em
-es -e
-ibus

6. pacis – is = pac Noun Stem Dictionary entry of a noun:
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
Nominative singular
Genitive singular
Gender
Meaning
pacis – is = pac
Noun Stem

7. Nominative Genitive Dative Accusative Ablative pax, pacis (f.) pax pac
Step 2: Add the case endings to the noun stem.
pax, pacis (f.)
Singular Plural
Nominative
Genitive
Dative
Accusative
Ablative
pax
pac
pac
pac
pac
pac
pac
pac
pac
pac
ibus
ibus e es is em es i um

8. Nouns and Adjectives
The adjectives you have learned thus far are called “1st/2nd declension adjectives”
Therefore, they do not use 3rd declension endings!
But what if you need to use an adjective to describe a 3rd declension noun?!?!

9. 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: sometimes nouns and adjectives have endings that AGREE but don’t MATCH.

10. 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…

11. Lex Bona “a good law”
Singular
Plural
Nom. lex bona leges bonae Gen. legis bonae legum bonarum Dat. legi bonae legibus bonis Acc. legem bonam leges bonas Abl. lege bona legibus bonis