We never say exactly what we mean, but we hint at what we want. We dance around the question instead of coming right out and saying what’s on our minds.
Listen to your characters speak. If you can’t hear them speak, then most probably what you want them to say, most often ought not to be said.
What differentiates each character is usually their word choice. This is key in shaping their voices. Forget the sound of the voice, forget the accent, forget pace. Just think of word choice.