YOU SAID:
I am so sorry for what my ancestors did
INTO JAPANESE
私の先祖がしたことにとても後悔しています
BACK INTO ENGLISH
I regret what my ancestors did
INTO JAPANESE
私は先祖の行いを後悔している
BACK INTO ENGLISH
I regret the actions of my ancestors
INTO JAPANESE
私は先祖の行為を後悔している
BACK INTO ENGLISH
I regret the actions of my ancestors
You've done this before, haven't you.