would have ... to him/her
Si j'avais su que Tom était à l'hôpital, je lui aurais rendu visite.
If I had known that Tom was in the hospital, I would have visited him.
Je lui aurais expliqué, il m'aurait peut-être pardonnée.
If I had explained it to him, he might have forgiven me.
— Andhadhun (2018)
S'il m'avait dit la vérité, je lui aurais pardonné.
If he had told me the truth, I would have forgiven him.
Si je l'avais su, je ne lui aurais jamais dit de telles choses.
If I had known, I would never have said such things to him/her.