If you are asked to speak about an unfamiliar subject, be sure to make the most of your research time. Study a wide variety of texts, videos and actual examples of your topic. Talk with people who know about it. When you speak, you can choose to talk about your research and share what you have learned rather than attempting to present yourself as an actual expert.
Always wear comfortable clothes for a speaking engagement. Even if you must wear a suit or formal dress, be sure your clothing fits properly and does not make you feel too hot. Choose modest clothing for Country Language, and make sure all fasteners and buttons hold securely so that you do not experience wardrobe malfunction.
Take your time while delivering your speech. One sure fired way for the audience to know that you are nervous is to rush through your speech. Instead, take a deep breath and calm your nerves before beginning. Speak slightly slower than normal when giving a speech to ensure that your audience understands what you are saying.