Rigorous sound correspondence is fundamental to historical linguistics. It serves as a solid start in studying genetic relationship. Regarding the genetic position of Miao-Yao languages, Li (1937) proposed a hypothesis that the Sino-Tibetan language family consists of Chinese, Tibeto-Burman, Kam-Tai, and Miao-Yao. Benedict (1942; 1975) excluded Miao-Yao from the Sino-Tibetan language family since sound correspondences between Miao-Yao and Chinese were considered to be caused by language contact. The key point in this debate has been ignored for a long time: are the related morphemes proposed in this debate supported by rigorous sound correspondence? In this paper, related morphemes across 11 Miao-Yao languages have been first identified under the requirement of complete sound correspondence, and then analyzed by the Rank Method. The result of the genetic relationship between the 11 Miao-Yao languages has been confirmed. The same procedure has been applied to Sino-Miao-Yao related morphemes, and similar pattern has been found. The Sino-Miao-Yao related morphemes were recognized to be inherited from the common ancestor of Chinese and Miao-Yao. Combined with the result from the perspective of pervasive sound correspondence (Wang 2015), the proposal of a genetic relationship between Chinese and Miao-Yao has been supported. The Inexplicability Principle has been used to weaken the possibility of Sino-Miao-Yao related morphemes being induced by borrowing from Chinese to Miao-Yao, since some sound correspondences are unlikely to be explained by natural phonetic mechanisms. Moreover, related morphemes in Chinese and Miao-Yao have been examined from the perspective of Old Chinese, and such an examination also supports the hypothesis of a genetic relationship between Chinese and Miao-Yao languages.
嚴格的語音對應是歷史比較的基礎，也是判定語源關係的必要條件。在苗瑤語的語源問題研究中，李方桂（1937）提出漢藏語系四語族學說，即漢語、藏緬語、侗台語和苗瑤語。Benedict（1942、1975）則將苗瑤語從漢藏語系中劃分出去，理由是苗瑤語和漢語有對應關係的語素是由接觸造成的。苗瑤語系屬問題的爭議焦點在於苗瑤語和漢語音近義同的一批關係語素是否有嚴格的語音對應支持，然而這一問題一直以來不被重視。本文基於完全對應得到苗瑤語族內部11個語言的關係語素，隨後應用詞階法分析，結果如願所示，這11個語言之間具有發生學關係。同樣的程序應用于漢-苗瑤語關係語素，結果與上述呈現的模式相同，即這些關係語素是來自漢語和苗瑤語共同的祖語，而非語言接觸的產物。結合普遍對應的研究（Wang 2015），漢語和苗瑤語的發生學關係可以得到支持。不可釋原則也顯示漢-苗瑤語關係語素是由苗瑤語從漢語借用的可能性較小，因為二者間的部分語音對應不可能通過自然音變來解釋。此外，從上古漢語的角度對漢-苗瑤語關係語素的校驗也支持二者的同源關係。
