摘要
由1932系統到1963－85系統間，單字聲調變化最明顯的趨勢是第一聲字的增加。本文檢視由中古音，中原音韻（代表十四世紀北方官話之主流，且不論是大都，洛陽，抑或商邱地區的話）至1932，1963－85幾個系統之間的單字聲調變化，統計出陰平調流入與流出的字數，發現「陰平化」的趨勢自中古音以來就一直存在。根據統計流入陰平調（由他聲一讀變為陰平一讀或分化為二讀，或由二讀併為陰平一讀）的字由中原音至1985系統共有345個；而流出陰平（由二讀變為他聲一讀或由陰平一讀分化為二讀）的字則僅38個。（由中古音到中原音韻之間流入與流出的字數根據此處粗略的統計是分別是9與1。）入聲字在派入三聲後變入或變向陰平的字數，由中原音至1932之間是：陽平1字（可能先變入去聲）；上聲79.5字（有一字上，去二讀）；去聲10.5字。由1932至1963－85之間是：陽平32字；上聲2.5字；去聲16.5字。另外有36字在中原音韻裏沒記錄。舒聲字由中原音至1932之間是：陽平字52.5個；上聲子19個；去聲字19.5個。由1932至1963－85之間是：陽平字13.5個；上聲字5個；去聲字9.5個。本文的統計與字例當可顯示出「陰平化」擴散的速度與幅度，以及單字聲調轉變的過程與形式。
The most prominent trend of tonal changes between the systems of 1932 and 1963-85 was the increase of First Tone characters. This paper examines the tonal changes from Middle Chinese, Old Mandarn (Zhong-yuan Yinyun, which was the mainstream of speech in the 14th century, be it the language of Dadu, Luoyang or Shangqiu), down to the 1932 and 1963-85 systems. A comparison of the statistics of characters changing into and those out of the First Tone reveals that there has been a steady inflow since the time of Old Mandarin. From Old Mandarin to the 1963-85 systems, a total of 345 characters have (1) changed from other categories to Yin Ping, or (2) developed an additional Yin Ping reading, or (3) merged from two readings into Yin Ping only. On the other hand, there have been only 38 characters that have changed from Yin Ping to other categories or developed an additional reading in other categories. (The corresponding figures for the period between Middle Chinese and Old Mandarin are 9 and 1, respectively, in this study.) There are also statistics of characters in terms of their source categories for different periods. The examples together with the statistics should afford an indication of the speed as well as the magnitude of this steady flow into the Yin Ping category. Furthermore, they also manifest the forms and processes of the tonal changes in individual characters.