Bullying isn’t just a playground problem. According to a recent survey released by the Workplace Bullying Institute, nearly 37 million workers have faced “abusive conduct” at work, while another 29 million had at least witnessed it. There are many types of bullying, ranging from physical or verbal assaults to situational bullying, where one party attempts to sabotage or deliberately humiliate a co-worker. To put a stop to workplace bullying, the behaviors first need to be recognized. There are common warning signs of bullying that workers should be aware of, whether they are the target or not. “Individuals can bully without being a bully," says Lynne Curry, author of Beating the Workplace Bully. "What distinguishes a bully from someone with normal bad behavior is that a bully engages in intentional repeated bullying behavior." When this repeated behavior is identified, it must be addressed decisively. Supervisors should have training to recognize troubling behavioral patterns and provide training for targets as well as bullies. It’s also important for HR to take bullying seriously and investigate all allegations with respect.