Ch 2 · Lesson 7Latin · Chapter 2 · Lesson 7 · Grammar primer
The third, fourth and fifth declensions
, : the third declension is the biggest family, and its stem hides in the genitive. Then and dies, two small families with very common words.
The short version
The third declension hides its own stem
, ; ,
Why?Hide
This is the whole argument for learning the genitive. You could not have guessed any of these from the nominative: becomes corpor-, becomes nomin-, becomes itiner-, becomes homin-, becomes reg-. The third declension is the biggest and holds a striking share of the commonest nouns, and all of its difficulty sits in the nominative singular.
The third declension
Genitive -. It is the largest family and holds a striking share of the most frequent nouns: , , and among them. All its difficulty is in the nominative singular. Once you have the stem, the endings are regular:
| Case | Singular | Plural |
|---|---|---|
| Nom | | |
| Acc | | |
| Gen | | |
| | |
| Abl | | |
A neuter such as , takes the same endings with the neuter rule applied:
| Case | Singular | Plural |
|---|---|---|
| Nom/Acc | | |
| Gen | | |
| | |
| Abl | | |
The one real complication is the i-stems, which take -ium in the genitive plural and -ia in the neuter plural: , of cities; , seas. They are on the third declension page.
The fourth and fifth
Small families, but a few very common words live in them. The fourth has genitive -us, with a -u- running through it:
| Case | Singular | Plural |
|---|---|---|
| Nom | | |
| Acc | | |
| Gen | | |
| | |
| Abl | | |
The fifth has genitive -. It is tiny, but (thing) and (day) are among the commonest nouns in Latin:
| Case | Singular | Plural |
|---|---|---|
| Nom | | |
| Acc | | |
| Gen | | |
| | |
| Abl | | |
runs the same way: . - I see the thing. Two exceptions earn a mention: is usually masculine, and (house) borrows second-declension forms, as in , at home, and , from home. Both are on the fourth and fifth declension page.
Adjectives do not have to match the family
An adjective agrees with its noun in case, number and gender, not in declension. uses second-declension endings and third-declension ones, and they agree perfectly, because the case is the same:
| Latin | English |
|---|---|
| a great king (subject) |
| a great king (object) |
| of a great king |
Same colour, different letters: that is agreement. The full rules are on adjectives and agreement.
Mistakes English speakers make
| Wrong | Right | Why |
|---|---|---|
rexem | | build on the genitive's , reg- |
corpum (object) | | a neuter's accusative is its nominative |
| | the adjective agrees in case |
learning | , | the genitive gives family and |
Going further: The genitive gives you the stem and the rest of the guide, when you want them. This lesson does not need them.
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Lesson 7 of 39 in this chapter