it is easy to be wise after the event
Definition:  after something bad has happened it is then when you understand that you could have done something to prevent it from happening
Usage:  if I knew that the house was built on disputed land, I would not have signed the purchase offer; talk about it is easy to be wise after the event

SEPEDI
Translation:  go bonolo go hlalefa ka morago ga moletlo
Proverb: ngwana o ganetšwa selepe, thipa o lesa ka noši

XITSONGA
Translation:  swa olova ku tlhariha endzhaku ka ntlangu
Proverb: mahlo ya nkwahle ya tiva hi muyevuri

TSHIVENḒA
Translation:  zwo leluwa u ṱalifha nga murahu nyito
Proverb: muḓivhatshikamba u ḓivha nga tshawe