who did it
I want to know who did it.
But you know who did it.
Eh bien, si tu ne l'as pas fait, alors qui l'a fait ?
Well, if you didn't do it, then who did?
Do you know who did it?
But I know who did it.
As-tu fini par découvrir qui l'a fait ?
Did you ever find out who did it?
I think I know who did it.