The play The Miracle Worker by William Gibson concerns the life of Helen Keller, who was struck down by an illness as a baby and consequently left blind and deaf. When Helen is six years old, Annie Sullivan arrives from the Perkins' Institute for The Blind and she is tasked with teaching Helen—not an easy undertaking but one with which Annie will persevere.
Dialogue refers to the actual words that are to be spoken by the characters and relies on the actors who are playing the characters to have an understanding of their subject matter. Together with stage directions, it reveals the plot of the story and helps develop the characters. In The Miracle Worker there are many stage directions that set the tone that is required and even the body language that is expected. This allows the audience to concentrate on the dialogue itself in developing the plot and understanding the setting.
The dialogue sets the scene in this play. For example, during a conversation between Martha and Percy, Martha says, "What she tryin’ do now?" The audience gleans information about the possible time period (early twentieth century) by the way the children speak and the location (the "South") from this discussion. James's character is also revealed in the dialogue. He has a dry sense of humor, often making inappropriate jokes, and his words also reveal his resentment towards the situation with Helen and the fact that he never meets his father's expectations. He purposefully provokes his father and the audience understands his feelings from his dialogue. He says "Father stands up, that makes it a fact," knowing that this comment will aggravate the situation in Act I when the family is discussing Helen's future before Annie's arrival is proposed. He continues with "You really ought to put her away, Father," which reveals that any reaction is better than none even if it does get him into trouble. In Act III, James says "But the world is him," which further reveals James's inability to reach his father or operate on the same level as he does.
Even Captain Keller's feelings are revealed in the dialogue—he can barely take any more. He is even giving up on finding a solution. He refers to any doctor as "a new quack" (Act I), revealing that he has lost faith in the medical profession's ability to help his daughter. Annie's words also reveal her character and the audience learns much about her patience, her determination and her understanding of Helen's frustrations just from her words. In Act III, it is significant that the word she is searching for in the dictionary is discipline, especially as this is exactly what Helen lacks. When Annie says, "Where’s disipline?" the audience learns that Annie cannot spell the word herself. The audience recognizes the enormous pressure on Annie to teach Helen "language" and how it is her determination, not her education, which will ultimately help Helen succeed.