不打不成器
bù​dǎ​bù​chéng​qì

spare the rod and spoil the child

  1. 不 bù adverb
    not
    Negative adverb used before verbs, adjectives, and other adverbs to indicate negation; also used as a bound-form prefix to form terms with opposite meanings
  2. 打 dǎ verb
    to hit
    to strike; to knock; to beat; to break
  3. 不 bù adverb
    not
    Negative adverb used before verbs, adjectives, and other adverbs to indicate negation; also used as a bound-form prefix to form terms with opposite meanings
  4. 成器 chéng​qì
    to become useful
    To grow up to be a useful person or a success; to become someone worthy of respect.