既往不咎原指已经做完或做过的事，就不必再责怪了。现指对以往的过错不再责备。

出自《论语·八佾》：“成事不说，逐事不谏，既往不咎。”

那么既往不咎用英语怎么说？

既往不咎可以用Let bygones be bygones，forgive somebody's past misdeeds，It is needless to blame things that are past，let the past be forgotten，be let off for one's past misdeeds，Let the dead bury their dead，not to censure sb. for his past misdeeds等来表示，例如：

1.在最为完善的自我修复体系中，既往不咎和逆来顺受的处世态度是最有效的治病良药。
In the most refined systems of self-healing, the ability to forgive and the ability to accept certain inevitable events are considered the greatest healers. 

2.目前，正在进行的人民行动党内外既往不咎的选举中，人民党承认它已经停止联络选民，过去常这样做。
In the election post-mortems currently being conducted within and without the PAP, the party acknowledges that it has ceased to connect with the voters as it once did. 

3.先前她激怒了他，他说，但他可以既往不咎，从头再来。
She had provoked him, he said, but he was willing to forget and start fresh. 

4.你为何不既往不咎，请他过来喝一杯酒呢？
Why don't you let bygones be bygones and ask him round for a drink? 

5.我们必须既往不咎。
We must let bygones be bygones.