Harriet the Spy is a classic children's book. It is a book that is best introduced around the 4th or 5th grade. The main character, Harriet, keeps a journal where she writes down everything she is thinking! This includes some not so very nice things about her friends, enemies, and anyone she happens to cross paths with.
When her journal is discovered and all of it's contents are shared to everyone she talked about , Harriet learns the hard way just how much words can hurt. She ends up friendless and miserable.
This is a wonderful story that can be used to show the importance of words. You could do several activities that show a child they should be very careful about what they say about one another. A teacher could have the class write one compliment about a friend to share with the class. Another good activity would be to have the class write a short story about something that was said about them, whether it be positive or negative, and how it made them feel.