slow down open your mouth so you don't mumble. I'm not sure what you mean by speaking clearly. So I'm assuming you have a communication disorder where you know what you want to say but are unable to get your point across clear enough for others to understand even though you have really intelligent things to say.You may also have difficulty in understanding what people say and tend to look at others doing things to see if you understood the directions. This is called a receptive and expressive disorder. I don't know how to help you with this problem or if there is any way of helping with this problem. Do some research you might figure it out.