Reconstruction:Proto-Slavic/vъ(n)

From Proto-Indo-European *h₁en (“in”). Often assumed to come from the zero-grade, cf. Lithuanian į; there are, however, no secure examples of *n̥ > Balto-Slavic *un (other examples like *sъto are all riddled with difficulties and unreliable), and the o-grade *h₁on can be posited instead.

*vъ(n)

1. (+ locative) in, inside, within (stationary)
2. (+ accusative) in, into, inside (motion to)
3. (+ accusative) at (a moment in time)
4. (+ locative) in, during (a period of time)

Because of the law of open syllables, the final -n was normally dropped. But when combined with a stem that (originally?) began with a vowel, it was attached to the following word.

• *jьz

• East Slavic:
  • Old East Slavic: въ (vŭ)
    • Belarusian: у (u), ў (ŭ), ва (va), ува (uva)
    • Russian: в (v), во (vo)
    • Ukrainian: у (u), в (v), ув (uv), во (vo), ві (vi), уві (uvi), вві (vvi)
• South Slavic:
  • Old Church Slavonic: въ (vŭ)
  • Bulgarian: в (v)
  • Macedonian: во (vo)
  • Serbo-Croatian:

    Cyrillic: у

    Latin: u

    • Chakavian: u, va
    • Kajkavian: v, vu
  • Slovene: v
• West Slavic:
  • Czech: v, ve
  • Polish: w, we
  • Slovak: v, vo
  • Sorbian:
    • Lower Sorbian: w
    • Upper Sorbian: w

• Vasmer (Fasmer), Max (Maks) (1964–1973), “в”, in Etimologičeskij slovarʹ russkovo jazyka [Etymological Dictionary of the Russian Language] (in Russian), translated from German and supplemented by Trubačóv Oleg, Moscow: Progress
• Derksen, Rick (2008), “*vъ(n)”, in Etymological Dictionary of the Slavic Inherited Lexicon (Leiden Indo-European Etymological Dictionary Series; 4), Leiden, Boston: Brill, →ISBN, page 530