Without fail, every class has problems with a school bully who picks on students in their own grade or even lower. Bullying can range from public embarrassment, emotional taunting, to actual physical threats. Most children are not raised to be confrontational because instead they are taught to be caring and helpful to others, or at least not to hurt others, so it can be difficult responding to someone who intimidates or angers you.
Bullies act the way they do because they thrive off the power that can be have an influence on someone else's feelings. They often come from backgrounds of insecurity and fear, which is why they want to be the ones in control to cause fear in others, in order to feel like they're overcome their own. Plus, it fulfills their need for attention when they know you will be on the lookout for any sight of them heading your way. However, there is a strong difference between bullies who just like to make you feel bad and those who actually want to scare you.
If you're dealing with someone who likes to put you down or embarrass you, the best way to get rid of their pestering you is to straight up confront them. It can be difficult and even embarrassing but it's the most impressive reaction a young person can have. It shows strength and determination, which is something a bully has trouble responding to. Just standing up for yourself takes away their perspective that you are weak and will take away their sense of power.
If this doesn't work right away, it helps to just keep a level head and continue showing resistance to their harsh words, especially if you have friends standing next to you. If it's your friend who is having problems with a school bully, you can stand by them with support without confrontational. If the bully's behavior increases in intimidation, then it is time to get an adult involved as this person may excalate into a physical bully.
If you're trying to get rid of a physical bully, the only true way to safely handle them is to go to a trusted teacher or staff member to get involved the instant things escalate. They say that strength comes in numbers, but getting your friends involved can quickly make a bad situation much worse. The last thing you want is a bigger confrontation. If you're friends and the friends of your bully stand face to face, the situation no longer has a victim but appears to be an equal battle. This does not bode well for your case that the bully is intimidating you. Your friends can help stand up for you but never attempt to look like they're there for physical backup.
If your bully has already resorted to aggresive behavior, the best thing you can do is catalog every encounter. Write down dates of confrontations with listed facts and maybe even photographs of any physical damage to your belongs or yourself. High school is a he said/she said world, so back yourself up with facts and evidence for support.