Don’t put yourself in a defensive attitude. Don’t talk as if you were trying to prove that you are telling the truth.
When you say a thing is so, state it as an undeniable fact. If it is a question of veracity, don’t protest violently that it is so, and altogether so, whether he believes it or not, and that you can prove it. State only facts, and assume that he believes you.
When a man asks you a direct question, answer it directly. Don’t dodge. Don’t go round about and begin with a lot of explanations. If he says, “How is this?” or “What about that?” don’t begin by saying, “Mr. So-and-so, when this company first went into business,” etc. Don’t give him a lot of ancient history, and gradually lead up to the answer to his question, nor lead away from it trying to make him forget it. Answer him directly, instantly, plainly.