one would have …
Un énorme serpent, on l'aurait vu.
A huge snake—we would have seen it.
— Harry Potter et la Chambre des secrets (2002)
Si le champ était magnétique, on l'aurait su au premier démarrage du tracteur.
If the field were magnetic, we would have known the first time we started the tractor.
— Interstellar (2014)
Si voter changeait quelque chose, on l'aurait interdit.
If voting changed anything, they would have banned it.
Il ne nous a rien dit, comme on l'aurait su ?
He didn't tell us anything, as if we would have known?
— Perfetti sconosciuti (2016)
Si la nature était une banque, on l'aurait déjà sauvée.
If nature were a bank, we would have already saved it.