his/her fault
He admitted it was his fault.
I don't think it's his fault.
He told me it was his fault.
Tutti sanno che non era colpa sua.
Everyone knows it wasn't his fault.
Dica loro che è stata tutta colpa sua.
Tell them it was all your fault.
Non era colpa sua se io non riuscivo ad amarla.
It wasn't her fault that I couldn't love her.
— Il segreto dei suoi occhi (2009)
Non pensa che fosse colpa sua.
He/She doesn’t think it was his/her fault.