If someone wants to inform or motivate an audience, or even has other objectives, usually, it means that they have to make a speech. It's very important that the communication be clear and efective. There are many guidelines to achieve this, for example: know the audience; get their attention; get organized etc. One very powerful tool to help the audience remember and retain what is being communicated is the Repetition. This is a common characteristic of a sucessful speech's structure.