What does "what a thing to have done" mean?
Native speaker’s answer
Rebecca
"What a thing to have done" indicates shock or surprise towards a person's actions. It's almost like scolding someone for an action without that person actually being there. It's not a very common way to show shock or surprise. It almost sounds too formal in English. I recommend using "Oh my god," "Wow," or "Oh dear." Ex: What a thing to have done! To lie to your family. Ex: She ran off to join a cult? Oh, what a thing to have done! Her poor family. Ex: A: Her son stole a bunch of money. B: What a thing to have done!