This Proto-Celtic entry contains reconstructed words and roots. As such, the term(s) in this entry are not directly attested, but are hypothesized to have existed based on comparative evidence.
This Proto-Celtic entry contains original research. The reconstruction in this entry is based on published research, but the specific form presented here is not found in prior works.



From Proto-Indo-European *h₁én. Matasović reconstructs *eni for the whole preposition,[1] but since the preposition triggers a nasal mutation/eclipsis instead of a lenition in its descendants, a closed syllable may be reconstructed instead. However, the attested closed syllable could be explained by the theory of the early apocope of final /i/ in unstressed words, usually used to explain the rise of the absolute and conjunct inflection in Old Irish (by treating conjunct forms in the unstressed category).[2]



  1. in

Derived termsEdit


  • Proto-Brythonic: *ɨn
    • Middle Breton: en
      • Breton: e
    • Cornish: yn, en
    • Old Welsh: in
      • Middle Welsh: yn
  • Old Irish: hi, i
    • Irish: i
    • Scottish Gaelic: an
    • Manx: ayns


  1. ^ Matasović, Ranko (2009) Etymological Dictionary of Proto-Celtic (Leiden Indo-European Etymological Dictionary Series; 9), Leiden: Brill, →ISBN, page 116
  2. ^ Bisagni, Jacopo. (2012). The Origins of the Preterite of the Old Irish Copula and Substantive Verb: An Overview and New Ideas. Journal of Celtic Linguistics, 14(1), 1-29, p. 9