早知今日，何必当初
zǎo​zhī​jīn​rì​hé​bì​dāng​chū

if I had known then what I know now

  1. 早知 zǎo​zhī
    to know in advance
    to know something ahead of time; to have prior knowledge
  2. 今日 jīn​rì adverbnoun
    today
    the current day; mostly used in formal or written contexts
  3. ， hé
    non-Chinese
  4. 何必当初 何必當初 hé​bì​dāng​chū
    why bother in the first place
    Why acted like that back then; expresses regret or reproach regarding past actions, often used in the phrase 早知今日，何必当初 zǎo​zhī​jīn​rì​hé​bì​dāng​chū.