Following are a number of back-translations as well as a sample translation for translators of Proverbs 15:4:

• Kupsabiny: “The words of a humble/gentle person makes people happy,
  but those of an arrogant person break down the stomach (causes loss of hope).” (Source: Kupsabiny Back Translation)
• Newari: “A good word gives life and health,
  but a cruel word wounds the heart.” (Source: Newari Back Translation)
• Hiligaynon: “A gentle words can-make- the life of a man -good, but a hurtful words can-cause- his heart -hurt.” (Source: Hiligaynon Back Translation)
• Kankanaey: “The gentle/quiet word, it-can-be-compared to a tree that gives life, but the crafty/tricky word, it extremely-much causes-sorrow/causes-hurt-feelings (lit. causes- the thoughts -to-be-painful).” (Source: Kankanaey Back Translation)
• English: “Those who speak kindly to people are like trees whose fruit gives life;
  speaking what is false causes people to despair/feel very discouraged.” (Source: Translation for Translators)