When you are making a statement, check if your voice rises at the end in an upward inflection. This sounds as though you are asking a question or requesting permission. You are not. You are making a solid, definitive point. If this is one of your tendencies, try saying the sentence again in a straight line rather than up a hill. There are plenty of reasons and opportunities to ask questions. Misplaced, upward inflections can diminish the excellence of your message.