Summarize this article:

The whole point of a verbal bully’s attacks is to unsettle you, so don’t give them the satisfaction. Stay calm, cool and collected despite any taunts or insults. To do this, it may help to  breathe deeply, count silently, or mentally repeat an affirmation, such as “I will remain calm.” Ignoring the person is an option. An even more powerful response, however, is to make it clear to the person that the remark doesn’t bother you. Make eye contact with the person, then shake your head in dismissal and look away. Most verbal bullying is carried out because the person hopes to offend you. If you can see any truth to their comment, throw the attacker off balance by agreeing with them. When you accept the statement, it loses its power and the attacker loses relevance. For example, someone says “You’re fat,” you might say “You’re right. I am fat." Avoid becoming defensive with the person. Instead, put the attacker in the hot seat by pulling apart their remark. Analyze the remark and ask questions about it.  For example, someone says, “You’re stupid.” You might respond with “Wow, stupid is such a strong word. Is there a reason you’re trying to insult me?”  However, if the bullying behavior is out of control or you feel unsafe, do not have any contact with the attacker. Just walk away. If you witness someone else being verbally attacked, help defend them by bringing the attacker's common decency into question. In response to their "bad parent" role, play the role of the overly kind parent.  For instance, if the attacker calls your friend a name, you might say, "Carl, name-calling doesn't look good on you. Show everyone that there's a decent human being under there somewhere." They'll likely feel shamed by their behavior and apologize.

Summary:
Remain calm. Dismiss the person’s attack. Agree with them, if it's true. Dismantle the attack. Play the kind parent.