Stay as close to the person as you can and be an emotional sounding board. Try to talk with them on the way to school or in between classes. Also, sit with them in the cafeteria, so they do not feel alone. If you are on the bus with the person, sit with them there too. Be a presence for them so that when bullying occurs, you will be there to stand up for them.
If the situation becomes dangerous, and it is possible that someone will get hurt, leave and go quickly get an adult. You can also encourage others to support the person being bullied. As soon as you see bullying occur, let others know that it’s not right. Always reassure the person being bullied that it isn’t their fault.