Persuasive speeches are designed to convince the audience of a speaker's point of view. If you're writing one, every element -- from your opening statement, to the main body and conclusion -- must reinforce that goal. Good persuasive speeches share several common characteristics. Those qualities include an opening statement that grabs interest, evidence that establishes your credibility and a conclusion that compels the listener to support your position or take action.
A persuasive speaker engages his audience from the start. One way is to open with a simple declarative statement and details that support your position. For example, a speaker on global warming might begin by saying, "There is little doubt that the planet is warming," states "Presentation" magazine. In your next few sentences, offer statistics to show how the Earth's climate is changing in ways that have negative impacts on human, animal and plant life. Lastly, introduce the consequences by saying something like, "If the ice caps melt, a vast majority of our countries' borders will be underwater."
Authority to Speak
Success in persuasive speaking hinges on how favorably the speaker's audience evaluates his credibility or competence. A speaker can draw on his expertise in an industry or subject to pre-empt common objections that an audience might raise. For example, a climatology professor or meteorologist would draw on his specialized knowledge to refute assertions that sudden climate shifts aren't serious. Credibility also comes from personal experience, which might prove more relevant to an ex-offender arguing the need to reform the criminal justice system, for example.
Structure is important for managing the flow of information in persuasive speeches. Most speakers make just two or three main points, with special emphasis on the first and last ones. One common option is problem-solution organization, in which you cite a problem and propose a way of addressing it. For more complex issues, consider the stock issues format of describing the problem, the harms that result and how you might remedy them. In other cases, it may be sufficient to make points sequentially, from beginning to end. Whatever format you use, make sure it's easy to follow.
Good speakers recognize the value of a balanced presentation. Many of the best remembered historical speeches are the shortest -- like the Gettysburg Address, which runs only 300 words, according to "Time" magazine. Time your speech while you're practicing it, so you can cut repetitious or unnecessary phrases. Also, make sure you spend roughly the same time on each main point. This approach gives your speech a steady, measured pace that's important in maintaining credibility with an audience.
The closing paragraph is your last opportunity to persuade listeners. You'll briefly review the main points once more, and then you'll state the actions you want audience members to take. For example, your global warming speech might close with an outline of measures -- such as planting more trees or starting recycling programs -- to ease pressure on the environment. Then finish with a statement that summarizes your purpose. For example, you might say, "These steps won't solve our problems overnight, but if everyone pitches in, they can change our planet for the better."