Peking opera is performed using both Classical Chinese and Modern Standard Chinese with some slang terms added for color. The social position of the character being played determines the type of language that he or she uses. Peking opera features three major types of stage speech ("nianbai"). Monologues and dialogue, which make up the majority of most plays, consist of prose speeches. The purpose of prose speech is to advance the plot of the play or inject humor into a scene. They are usually short, and are performed mostly using vernacular language. However, as Elizabeth Wichmann points out, they also have rhythmic and musical elements, achieved through the "stylized articulation of monosyllabic sound units" and the "stylized pronunciation of speech-tones", respectively. Prose speeches were frequently improvised during the early period of Peking opera's development, and "chou" performers carry on that tradition today.