What is verbal bullying?

Verbal bullying takes place offline, it could range from someone spreading rumors to saying nasty and hurtful comments.

How do I prove it?

In my opinion, verbal bullying is the hardest to prove. It's your word against theirs. I reccomend that you walk around with a friend or family member who knows what is going on and can help you prove that your being bullied.

How do I show that I am being bullied verbally?

You could write down everything that the bullies say.
Hang around with friends.
Stay away from them.
Report them to a teacher or responsible adult.