Proto-Hmongic or Proto-Miao (Chinese: 原始苗语)[1] is the reconstructed ancestor of the Hmongic languages.
In China, the first comprehensive reconstruction of Proto-Hmongic (Proto-Miao) was undertaken by Wang Fushi (1979).
[3] The Proto-Hmongic tonal category C is derived from Proto-Hmong–Mien final *-k, while tonal category D in Proto-Hmongic is derived from Proto-Hmong–Mien finals *-p and *-t. Below are some examples of Proto-Hmongic tone C corresponding to Proto-Mienic tone D and Proto-Hmong-Mien final *-k.[3] Although Proto-Hmongic does not have explicitly reconstructed final stops (i.e., *-p, *-t, *-k), Pa-Hng and Qo Xiong have vowel quality distinctions that correspond to whether the Proto-Hmong-Mien rime was open or closed.
For example:[3] Qo Xiong has -u for words developed from Proto-Hmong-Mien forms with closed rimes, while Qo Xiong words developed from Proto-Hmong-Mien forms with open rimes have -ə.
[4] Ostapirat (2016) proposes velarized initials in Proto-Hmongic, which are not reconstructed by Ratliff (2010) and others.