恨铁不成钢
hèn​tiě​bù​chéng​gāng

to be disappointed that someone falls short of expectations

  1. 恨 hèn verb
    to regret
    to regret; to feel remorse; to be exasperated by one's own mistakes or a situation
  2. 铁 鐵 tiě noun
    iron
    iron (Fe); the metal used for making steel and tools
  3. 不成 bù​chéng
    to fail
    (bound form) to fail to happen; to not become something; to have no success or achievement
  4. 钢 鋼 gāng noun
    steel
    steel; an alloy of iron and carbon that is tougher than cast iron and harder than wrought iron