Declining third declension adjectives
Third declension adjectives can be split into I stems and consonant stems.
The majority of third declension Latin adjectives are classed as I stems , so called because the stems in the ablative singular for all genders end in i. Consonant stems form a much smaller group and are declined separetely.
* Third declension adjectives. I stems
There are I stems, I stems and I Stems. I stems, are split (decline differently) depending on the ending of the adjective in nominative singular masculine, feminine and neuter.
Third declension adjectives with the ending -is, -is, -e
Adjectives (I stems) which have the endings -is, -is, -e in the nominative singular are declined as tristis, is, e (sad).
Singular
| M. | F. | N. |
|---|---|---|
| tristis | tristis | triste |
| tristis | tristis | triste |
| tristem | tristem | triste |
| tristis | tristis | tristis |
| tristi | tristi | tristi |
| tristi | tristi | tristi |
Plural
| M. | F. | N. |
|---|---|---|
| tristes | tristes | tristia |
| tristes | tristes | tristia |
| tristes | tristes | tristia |
| tristium | tristium | tristium |
| tristibus | tristibus | tristibus |
| tristibus | tristibus | tristibus |
Third declension Latin adjectives (I stems) which have the same endings in the masculine, feminine and neuter in the nominative singular are declined like ingens (huge).
Or like felix,felix,felix depending on the endings.
| M. | F. | N. |
|---|---|---|
| ingens | ingens | ingens |
| ingens | ingens | ingens |
| ingentem | ingentem | ingens |
| ingentis | ingentis | ingentis |
| ingenti | ingenti | ingenti |
| ingenti | ingenti | ingenti |
Plural
| M. | F. | N. |
|---|---|---|
| ingentes | ingentes | ingentia |
| ingentes | ingentes | ingentia |
| ingentes | ingentes | ingentia |
| ingentium | ingentium | ingentium |
| ingentibus | ingentibus | ingentibus |
| ingentibus | ingentibus | ingentibus |
Third declension Latin adjectives with endings -er, -ris, -re
Third declension Latin adjectives (I stems) which have the endings -er, -ris, -re for the masculine, feminine and neuter in the singular are declined like acer (keen).
In a dictionary, acer could be cited as acer, acris, acre or ac/er -ris
Singular
| M. | F. | N. |
|---|---|---|
| acer | acris | acre |
| acer | acris | acre |
| acrem | acrem | acre |
| acris | acris | acris |
| acri | acri | acri |
| acri | acri | acri |
Plural
| M. | F. | N. |
|---|---|---|
| acres | acres | acria |
| acres | acres | acria |
| acres | acres | acria |
| acrium | acrium | acrium |
| acribus | acribus | acribus |
| acribus | acribus | acribus |