Dictionary form and gender endings
When you open a Latin dictionary, adjectives of the first group are always presented in a strictly defined format. This dictionary form contains the masculine form in the nominative singular (Nom. sing.), as well as the endings for the feminine and neuter genders.
There are two main variants of standard endings for this group:
- The first variant consists of adjectives that end in -us in the masculine. In the feminine, they take the ending -a, and in the neuter, the ending -um. A classic example of such a word is longus, a, um (long).
- The second variant comprises words whose masculine form ends in -er. Exactly the same endings, -a and -um, are used for the feminine and neuter genders. For example, dexter, tra, trum (right) or liber, era, erum (free).
Distribution across declensions
The main feature of the first group is that it combines two different types of Latin declension at once. To decline a word correctly, you must strictly monitor its gender.
Feminine forms (those ending in -a) are declined exclusively according to the rules of the 1st declension. In the genitive singular (Genitivus singularis), they receive the standard ending for this declension, -ae. For example, the genitive form for longa will be longae, and for libera — liberae.
Masculine forms (with endings -us or -er) and neuter forms (with the ending -um) follow the rules of the 2nd declension. Consequently, in the genitive singular, they will have the characteristic ending -i. Thus, longus becomes longi, and longum also becomes longi.
| Genus | Declension | Ending (Gen. sing.) | Example form |
|---|---|---|---|
| Feminine | 1st declension | -ae | longae, liberae |
| Masculine | 2nd declension | -i | longi, liberi |
| Neuter | 2nd declension | -i | longi, liberi |
Features of -er adjectives
The greatest difficulty is caused by adjectives whose dictionary form in the masculine ends in -er. When forming oblique cases, as well as feminine and neuter forms, the stem of such words can behave in two ways: the vowel "e" either disappears or remains in place.
- With the omission of the vowel "e".
It disappears from the stem in all feminine and neuter forms, as well as in the masculine starting from the genitive case. Let us examine this process using the word ruber, bra, brum (red). In the nominative case, we see the forms ruber, rubra (not rubera), rubrum. In the genitive singular, the vowel "e" is also absent: rubri, rubrae, rubri.
- With the retention of the vowel "e".
In this case, the letter remains in the root of the word in absolutely all case forms of all three genders. A striking example of this behavior is the word liber, ěra, ěrum (free). In the nominative case, the forms appear as liber, libera, liberum. Upon transition to the genitive case, the stem does not lose the vowel: liberi, liberae, liberi.
Briefly: answers to topical questions
Which medical adjectives in -er retain the vowel "e" during declension?
The vowel "e" is retained during declension in all forms of the following first-group adjectives in -er:
- Free (liber, era, erum)
- Rough (asper, era, erum)
In these words, the letter "e" is not dropped when declining through cases. For example, in the genitive singular, the forms liberi, liberae and asperi, asperae are formed.
Which anatomical adjectives in -er lose the vowel "e" in oblique cases?
The vowel "e" is dropped in the masculine starting from the genitive case, as well as in the feminine and neuter genders in all cases for the following adjectives:
- Red (ruber, bra, brum)
- Sacral (sacer, cra, crum)
- Black (niger, gra, grum)
- Right (dexter, tra, trum)
- Left (sinister, tra, trum)
For example, in the genitive singular, they have the forms rubri, rubrae and sacri, sacrae.
How to correctly agree a first-group adjective with a feminine noun of the 4th declension?
For correct agreement, you must put the adjective in the feminine form, since the choice of form depends on the gender of the noun being modified. A first-group adjective in the feminine takes the ending -a and is always declined according to the 1st declension. The declension of the noun itself (in this case, the 4th declension) does not affect the adjective's declension type.
How is the adjective dexter declined in the feminine across all cases?
The sources do not present a complete paradigm of declension across all cases. It is only indicated that the dictionary form of the word is dexter, tra, trum. In the feminine, the adjective has the form dextra (ending -a) and is declined according to the 1st declension. In the genitive singular (Genitivus singularis), it takes the ending -ae.
To easily understand whether the "e" drops in an -er adjective, simply look at its dictionary entry. If the dictionary indicates "ruber, bra, brum", it means the letter "e" has already disappeared in the abbreviations for the feminine (bra) and neuter (brum) gender, and it will not be present in other cases either.
Class and exam questions
How to determine which declension to use for a first-group adjective?
You need to look at the gender ending. If the word is in the feminine gender (ends in -a), apply the 1st declension. For the masculine (-us, -er) and neuter (-um) genders, always use the 2nd declension.
Do -er adjectives always drop the root vowel?
No, there are two variants. In some words (e.g., ruber, bra, brum), the vowel "e" drops, while in others (e.g., liber, era, erum), it is retained in all forms.
What ending will the word dexter have in the feminine genitive case?
The dictionary form of this word is dexter, tra, trum. The feminine form in the nominative is dextra. In the genitive case, according to the rules of the 1st declension, it will receive the ending -ae, therefore, the correct answer is dextrae.
What else to study on this topic
- Complete paradigm of 1st declension case endings
- Complete paradigm of 2nd declension case endings
- Rules for agreement of first-group adjectives with nouns
- Vocabulary minimum of medical adjectives of the first group
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Other topics in the section "Adjective. Agreement"
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