Some words draw on experiences that persist across the generations and that cross most cultural boundaries. They express many of the needs , and can be especially useful for diverse groups. Among them is a set of metaphors that seem especially powerful and popular in speeches. These metaphors connect their particular, time bound subjects with timeless themes: With light and darkness, storms, the sea, disease, war, the impulse to build, the family, and space. They tap into the human experience. A brief look at three of these metaphors demonstrates their potential power in communication.
Light and Darkness. From the beginnings of time, people have made negative associations with darkness. The dark is cold, unfriendly, and dangerous. On the other hand, light brings warmth and safety. It restores one’s sense of control. When speakers use the light-darkness metaphor, they usually equate problems or bad times with darkness and solutions or recovery with light.

Beyond a general purpose, a speech should also have a specific purpose. For example, an informative speech may have the specific purpose of increasing listeners’ knowledge of the causes of global warming. The specific purpose of a speech will typically be evident by the time the speaker finishes the introduction, and must be unmistakably clear by the time the speaker begins the conclusion.
A speech that lacks a clear sense of purpose will seem to drift and wander as though it were a boat without a rudder, blown this way and that by whatever thought occurs to the speaker. Developing a clear purpose begins with the speaker considering audience needs. Speakers must determine precisely what they want to accomplish: what they want listeners to learn, think, or do as a result of their speeches.

The organization of the body of the speech will vary according to the subject and purpose. If a speech tells you how to do something—for instance, how to plan a budget—its main points should follow the order of the process that it describes. If the subject breaks naturally into parts, such as the three major causes of global warming, speakers can use a categorical design to present them.
A variety of concluding techniques can be used to end a speech. If speakers have covered several main points in the body, they should summarize them and then make a final statement that will help the audience remember the essence of the message.
Effective speeches also contain transitions that link together the various parts of the speech. Transitions bridge ideas and aid understanding. They signal that something different is coming and help the speech flow better. Transitions should be used between the introduction and body of a speech, between the body and the conclusion, and between the main points within the body.

Any speech worth listening to will bring something new to you. The topic should be fresh and interesting. If the topic has been overused, then the speech must be innovative to sustain attention. One frequently overused topic for persuasive speeches is drinking and driving. When speakers choose such a topic, they can’t simply reiterate the common advice “if you drink, don’t drive” and expect to be effective. The audience will have heard that message hundreds of times. To get through to listeners on such a subject, speakers have to find a fresh way to present the material. One student of ours gave a speech on “responsible drinking and driving” that stressed the importance of understanding the effects of alcohol and of knowing your own tolerance limits. Her fresh approach and important information gave us a new perspective on an old problem.