GIVE ANSWERS - Français

Both ”his” and ”her” are correct/possible translations, if this sentence is not in some context. With just the sentence ”C’est son chien”, you don’t know if the dog belongs to a woman or a man.

Both translations are correct, depending on the gender of the dog’s owner. If the owner is a woman, ”it’s HER dog”. If the owner is a man, ”it’s HIS dog”. In French the possessive pronouns follow the object possessed, not the owner.