From Proto-Italic *-nos, from Proto-Indo-European *-nós.
-nus (feminine -na, neuter -num); first/second-declension suffix
The suffix -nus is appended to a verbal root to form an adjective and nouns.
This suffix survived in inherited forms and became productive through its derivations (cf. infra) by metanalysis (e.g. starting points may be the class of u stem tribus, from which tribū-nus, later interpreted as trib-ūnus).
First/second-declension adjective.
Number | Singular | Plural | |||||
---|---|---|---|---|---|---|---|
Case / Gender | Masculine | Feminine | Neuter | Masculine | Feminine | Neuter | |
Nominative | -nus | -na | -num | -nī | -nae | -na | |
Genitive | -nī | -nae | -nī | -nōrum | -nārum | -nōrum | |
Dative | -nō | -nō | -nīs | ||||
Accusative | -num | -nam | -num | -nōs | -nās | -na | |
Ablative | -nō | -nā | -nō | -nīs | |||
Vocative | -ne | -na | -num | -nī | -nae | -na |
Ultimately the same as the above, but apparently rebracketed at some point as *-sno- (extracted from words like *tris-no-, the original form of ternus).
-nus (feminine -na, neuter -num); first/second-declension suffix
In pre-Latin, the suffix *-nos (Classical Latin -nus) was attached to numeral adverbs, cardinal numerals, or numeral stems to form distributive numerals, such as
At some point in pre-Latin, the suffix seems to have become extended to *-sno-, presumably as the result of rebracketing of forms like *tris-no- as *tri-sno-, *dwis-no- as *dwi-sno- or *seks-no- as *sek(s)-sno-. By the time of Classical Latin, *-s- before *-n- had been lost by regular sound change, but it caused any preceding nasal or plosive consonants to be deleted and the preceding vowel to be lengthened. Thus, it can be inferred that the *-sno- variant of the suffix was used to form words like the following:
The -ēno- found in decades such as vīcēnus, trīcēnus probably developed from -ent-sno-.
Then the ending -ēnus seems to have been extended from some of the above forms and used as a third allomorph of this suffix to form some of the other distributive numerals:
First/second-declension adjective (distributive, normally plural-only; short genitive plurals in -num preferred).
Number | Singular | Plural | |||||
---|---|---|---|---|---|---|---|
Case / Gender | Masculine | Feminine | Neuter | Masculine | Feminine | Neuter | |
Nominative | -nus | -na | -num | -nī | -nae | -na | |
Genitive | -nī | -nae | -nī | -num -nōrum |
-num -nārum |
-num -nōrum | |
Dative | -nō | -nō | -nīs | ||||
Accusative | -num | -nam | -num | -nōs | -nās | -na | |
Ablative | -nō | -nā | -nō | -nīs | |||
Vocative | -ne | -na | -num | -nī | -nae | -na |
Via -ēnus: