Nouns of the second declension all end in -i in the genitive case. Unlike first declension nouns, which all have the same -a ending in the nominative, their nominative endings can differ, so we use the genitive ending to recognize them as second declension nouns. Most masculine second declension nouns end in -us, -ius, or -er in the nominative case.
Nouns of the second declension may be masculine or neuter, just as nearly all first declension nouns were feminine. We will only focus on the masculine nouns in this lesson. The second declension masculine endings are:
| Case | Singular | Plural |
|---|---|---|
| Nominative | (varies) | -i |
| Genitive | -i | -orum |
| Dative | -o | -is |
| Accusative | -um | -os |
| Ablative | -o | -is |
If you compare these endings to the first declension endings, you'll see some similarities that may help you remember them. The dative and ablative are the same, as they were in the first declension plural, and the genitive plural has a 'rum' sound.
We decline a noun by adding these endings to the stem, which is found by removing the -i from the genitive. Let's start with a -us word, amicus, amici, meaning “friend”.
| Case | Singular | Plural |
|---|---|---|
| Nom. | amicus | amici |
| Gen. | amici | amicorum |
| Dat. | amico | amicis |
| Acc. | amicum | amicos |
| Abl. | amico | amicis |
Now we'll do one that ends in -er: puer, pueri, meaning “boy”.
| Case | Singular | Plural |
|---|---|---|
| Nom. | puer | pueri |
| Gen. | pueri | puerorum |
| Dat. | puero | pueris |
| Acc. | puerum | pueros |
| Abl. | puero | pueris |
Here's another -er word, ager, agri, meaning “field”. Note that unlike puer, ager drops the 'e' in the genitive. Remember that we get the stem for forming all the cases from the genitive, not the nominative; so we always learn the genitive along with the nominative when we learn a new word.
| Case | Singular | Plural |
|---|---|---|
| Nom. | ager | agri |
| Gen. | agri | agrorum |
| Dat. | agro | agris |
| Acc. | agrum | agros |
| Abl. | agro | agris |
And here's one ending in -ius: filius, fili, meaning “son”. Nouns like filius are slightly different, in that they drop the extra -i in the genitive singular. So the stem is actually fili-, but the genitive is fili, not filii. All other forms are as expected, adding the endings to the stem fili:
| Case | Singular | Plural |
|---|---|---|
| Nom. | filius | filii |
| Gen. | fili | filiorum |
| Dat. | filio | filiis |
| Acc. | filium | filios |
| Abl. | filio | filiis |
As mentioned above, the vocative only differs from the nominative in the second declension singular, and only in nouns ending in -us and -ius. Filius and proper names ending in -ius (like Lucius) form the vocative with -i:
Nouns ending in -us form the vocative with -e:
One exception to this last rule is deus, meaning “god”. The vocative of deus is deus. So in prayers starting with “O God,” you'll see Deus, not Dei or something like that.
As we touched on very lightly before, possession is shown by the genitive case:
The owner may come before or after the thing owned, but you'll normally see the two words together in the sentence. When translating to Latin, try not to put a genitive between two nouns, since that would make it hard to tell which thing is being owned.
a. Translate:
b. Translate:
c. Think of an English word derived from each Latin word in the vocabulary.
Now we've learned enough words and forms to start making some real sentences. Next lesson: our first neuter nouns, plus more uses of the accusative and ablative. This lesson can be discussed here.
a. Translate:
b. Translate:
c. Think of an English word derived from each Latin word in the vocabulary.