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• Russian
  откры́тьotkrytʹ

  ɐtˈkrɨtʲinherited

  Отвори́ть, the cognate of the West and South Slavic words, is used of doors.

• Ukrainian
  відкри́тиvidkryty

  ʋʲidˈkrɪtɪinherited

  For doors and windows Ukrainian prefers відчини́ти.

• Polish
  otworzyć

  ɔˈtfɔʐɨtɕdifferent word · Proto-Slavic *otъvoriti / *otъverti 'un-shut'
• Czech
  otevřít

  ˈotɛvr̝iːtdifferent word · Proto-Slavic *otъvoriti / *otъverti 'un-shut'

  The strong yer of *otъ- surfaces as ote-.

• Bosnian-Croatian-Serbian
  otvoritiотворити

  otˈvoritidifferent word · Proto-Slavic *otъvoriti / *otъverti 'un-shut'
• English
  to open

Sound laws at work

• The fall of the yers
• Ukrainian і (ikavism)