в-

• во- (vo-) – before certain consonant clusters

Inherited from Old East Slavic въ- (vŭ-), from Proto-Slavic *vъ(n)-, from Proto-Indo-European *h₁én. The /n/ persists in внять (vnjatʹ). See also в (v), Old East Slavic въ (vŭ), Proto-Slavic *vъ(n). Compare the similar development in с- (s-) from Proto-Slavic *sъ(n)-.

• IPA^(key): [v] (before vowels and voiced consonants)
• IPA^(key): [f] (before voiceless consonants)

в- • (v-)

1. added to verbs, forms verbs with the approximate meaning 'in' or 'into'

   ‎во- (vo-) + ‎-йти́ (-jtí, “to go”) → ‎войти́ (vojtí, “to go in, to enter”)

2. added with -ся (-sja) to verbs, forms verbs with the approximate meaning of thoroughness or completeness of action

   ‎в- (v-) + ‎чита́ть (čitátʹ, “to read”) + ‎-ся (-sja) → ‎вчита́ться (včitátʹsja, “to read carefully, delving into the content to better understand”)

3. added to adjectives, forms adverbs with the approximate meaning 'in the manner of [the adjective]'

   ‎в- (v-) + ‎ручно́й (ručnój, “(relational) hand; manual”) → ‎вручну́ю (vručnúju, “manually (by hand)”)

4. added to nouns, forms adverbs with the approximate meaning 'in the direction or location of [the noun]'

   ‎в- (v-) + ‎нутро́ (nutró, “the inside”) → ‎внутри́ (vnutrí, “inside”)

   ‎в- (v-) + ‎низ (niz, “the bottom”) → ‎вниз (vniz, “downwards”)

5. added to numerals, forms adverbs based on the numeral

   ‎в- (v-) + ‎дво́е (dvóje, “two (in a group together)”) → ‎вдво́е (vdvóje, “twice, by half”)

   ‎в- (v-) + ‎дво́е (dvóje, “two (in a group together)”) → ‎вдвоём (vdvojóm, “as a two”)

• в (v)