Horpa (also known in some publications as Stau – Chinese: 道孚语 Daofu, 爾龔語 Ergong) are a cluster of closely related Gyalrongic languages of China.

The term Stodsde skad is a Tibetan name meaning "language of the upper village".

[6]The cluster of languages variously referred to as Stau, Ergong or Horpa in the literature are spoken over a large area from Ndzamthang county (in Chinese Rangtang 壤塘县) in Rngaba prefecture (Aba 阿坝州) to Rtau county (Dawu 道孚) in Dkarmdzes prefecture (Ganzi 甘孜州), in Sichuan province, China.

/r/ has four allophones as either retroflex voiceless [ʂ] or voiced [ʐ] fricatives, as a trill [r], or as a result of vowel rhotacization [V˞].

It is heard as [ʐ] when in free variation in initial position or when preceding or following voiced consonants.

The occurrence of it as a trill [r] is heard word-medially when after a vowel and before a consonant, but is for the most part less predictable in that it overlaps in distribution with [ʂ] and especially [ʐ].

Jacques et al. (2017)[7] list the following words as lexical innovations shared by Stau and Khroskyabs (Lavrung), but not by the Core rGyalrong languages.

Shangzhai Horpa (Puxi Shangzhai) is a dialect of the Horpa language noted by a single consistently non-syllabic causative prefix "s-", which exerts pressure on the already elaborate onset system and triggers multiple phonological adjustments (Sun 2007).

[23] As a Qiangic language, Horpa has unique verb inflection and morphology such as the strategy of inverting the aspiration feature in the formation of the past and progressive stem(s) (Sun 2000).