Following are a number of back-translations as well as a sample translation for translators of Isaiah 28:18:

• Kupsabiny: “Your agreement with death shall be removed
  and the things you have agreed shall not come to pass
  (agreed) with the world of the dead.
  When disaster comes to you (plur.)
  (it) shall defeat you completely.” (Source: Kupsabiny Back Translation)
• Newari: “Your covenant with death will be broken;
  your agreement with the grave of the dead will no longer.
  When the scourge came like flood,
  you will be covered by it.” (Source: Newari Back Translation)
• Hiligaynon: “Your (plur.) covenant with death will-be useless, and what you (plur.) had-agreed with the place of the dead-ones. For when the disaster will-come like a flood, your (plur.) will-be-destroyed.” (Source: Hiligaynon Back Translation)
• English: “I will annul/destroy the agreement that you made with the leaders of Egypt.
  You thought that because of that agreement you would not be killed, and you would not go to the place where the dead are.
  But when the vast army of Assyria overwhelms you like a flood,
  they will trample you into the ground.” (Source: Translation for Translators)