You're standing with your classmates. Everyone is talking except you. Perhaps you're afraid they will laugh at what you say.Maybe you just aren't brave enough to speak.
Shyness is like a snake that crawls into our mouth and stops us speaking. But we shouldn't let it stay there.
I am 29 years old. Even today, that snake still sometimes visits me. But when I was in high school, I was so shy that I wouldn't talk to anyone except my parents and best friends. If a stranger asked me the way to a local shop, it was as if I'd forgotten how to talk.One summer, I got a job in a restaurant and that helped a lot. It meant I had to talk to customers. I had to tell them how much their meal cost. I had to ask them whether they want to drink Coke or Sprite. This job taught me how to speak with people.
You may not be to young to find a part-time job. But you can look for other chances to speak with people. You can offer to help an old woman carry her heavy bag. Or you can go to get a newspaper for your family.
If you do these things for the first time, the “shyness” snake will soon begin to leave you alone. It'll look for another mouth to crawl into.