fire

• Russian
  ого́ньogonʹ

  ɐˈɡonʲinherited

  A fire that burns a building down is пожар.

• Ukrainian
  вого́ньvohonʹ

  ʋɔˈɦɔnʲinherited

  Ukrainian adds a v- before initial o-, as in вогонь and вухо.

• Polish
  ogień

  ˈɔɡjɛɲinherited
• Czech
  oheň

  ˈoɦɛɲinherited
• Bosnian-Croatian-Serbian
  vatraватра

  ˈvatradifferent word · a Balkan word shared with Romanian vatră 'hearth'; its ultimate origin is debated

  The cognate oganj is literary.

• English
  fire

Sound laws at work

• The fall of the yers
• g → h (spirantization)