The so-called н-declension of this and nine other similar neuter nouns are remnants of sound changes that took place in Common Slavic due to the the Law of Open Syllables: a requirement that syllables could not have decreasing sonority. While Late Proto-Indo-European and Late Proto-Slavic had nasal diphthongs consisting of a vowel plus a nasal consonant (/m, n/), such syllables later violated the Law of Open Syllables in Common Slavic since a consonant is inherently less sonorous than a vowel and thus a nasal diphthong would have falling sonority. This problem was remedied by the transition of such nasal diphthongs into nasal vowels through a process of monophthongization. In Proto-Slavic, the nominative singular contained the syllable /mĕns/. After the loss of the final consonant, the remaining nasal diphthong, which violated the Law of Open Syllables, was reduced to a nasal vowel /ę/ represented by Ѧ, ѧ (little yus) in Old Church Slavonic and Late Proto-Slavic, eventually becoming word-final -я in modern Russian. In the oblique cases, because the /n/ sound appeared at the beginning of a syllable (due to all the oblique case endings beginning with a vowel), there was no nasal diphthong to violate the Law of Open Syllables and the -ен- was preserved before all the oblique case endings in the modern language. Compare the declension of Old Church Slavonic имѧ (imę).
- name, first name, Christian name, given name (for inanimate things, see назва́ние (nazvánije))
- (grammar) noun (broad sense)
и́мя существи́тельное ― ímja suščestvítelʹnoje ― noun (narrow sense), substantive
и́мя прилага́тельное ― ímja prilagátelʹnoje ― adjective
и́мя числи́тельное ― ímja čislítelʹnoje ― numeral
- полуи́мя (poluímja)