Children are sensitive and a parent should not be giving negative judgements or opinions. Even when speaking in general, everyone needs encouragement in order to achieve goals. Verbal abuse will only lower a person's self-esteem; this could lead to mental disorders, suicidal thoughts and things along that line. Children, especially, need love and encouragement from their parents.
The word abuse was in the title. Anyone that disagrees needs reread the subject line.
Abuse is an issue, therefore. Rather you're a child or an adult; abuse is an issue that can lead to depression. Depression is a mental illness that can lead to a person being unstable. Therapy and prescriptions are required in these situations. Abuse can be considered as criminal harassment. Are we not supposed to take actions against criminal harassment? Amanda Todd was verbally abused before she committed suicide. These are children who deserve to grow up in a healthy mental state. They are our future generation. You decide.
It depends on the child's personality on how to approach the subject. If the child is comfortable in social situations; you can tell them how to vocally express their displeasure civilly with the bully. If the child is rather shy; there should be a conference with the bully's parents and the bully. If an adult is verbally abusing a child, I am not particularly sure what can be done legally. But no one deserves to be spoken to in such a way. The parents should pride themselves in teaching their children to live positively and not put others down.