An argumentative essay is where you have a claim, evidence, and reasoning. First you make a claim to let the audience know how you feel about a particular topic. Then you back it up with evidence. Finally you give your reasoning; why you feel this way, and why you want to argue for it, or against it. I think school uniforms would be a good topic because it's so debatable. Teen driving would be another good one; there are many statistics to back your claim up with that. Writing an argumentative essay is fairly easy, as long as you know what you're talking about.