abstract:A pentagraph (from the , pénte, "five" and γράφω, gráphō, "write") is a sequence of five letters used to represent a single sound (phoneme), or a combination of sounds, that do not correspond to the individual values of the letters. In German, for example, the pentagraph tzsch represents the sound of the English digraph ch, and indeed is found in the English word Nietzschean.