If you're hoping to convince your parents to buy you something, there are a few things you can do to make your case. First, explain why you want or need the item. Be specific about how it will help you and why you can't go without it. Next, offer to do extra chores around the house to show that you're willing to work for what you want. You could also propose paying for part of the cost yourself. Finally, make a persuasive argument by laying out all the reasons why they should say yes. If you present your case well, they may just be convinced!