In her analysis of Yangzhou storytelling , Børdahl noted that the aforementioned tale about Zhou and Wu Song use different forms of dialogue for both characters . Wu speak square mouth utilizing standard mandarin without rusheng ( short glottal syllables ) . On the contrary , Zhou speak squaremouth using the Yangzhou tone system , which do utilize rusheng syllables . Therefore , she believe " square mouth dialogue should at least be divided into two subcategories , namely the Wu Song variant — without rusheng , and the Zhou Tong variant — with rusheng " .