Mongolian Sha: The Second Sibilant

Sha writes the voiceless palato alveolar sibilant, the sound spelled sh in English, and it is the seventeenth letter of the alphabet. Mongolian has both sibilants natively and keeps them apart, and the alphabet supplies a separate letter for each, inherited from the same Aramaic ancestry that gave it the plain s. Unicode encodes sha at U+1831. The two sibilants behave differently in the history of the language, and one of the differences is visible in the vocabulary: the palatal sibilant is common before certain vowels in native words and turns up constantly in words taken from Tibetan and Sanskrit, where it renders more than one distinct source sound. That is the point at which two letters stop being enough. Sanskrit distinguishes three sibilants, and a Mongolian scribe writing a Sanskrit name accurately needs to mark distinctions the Mongolian alphabet was never built to carry.

The extended signs encoded under the name Ali Gali exist for this, alongside the ten letters added at the end of the alphabet for other foreign sounds. A reader meeting an unfamiliar sibilant shape in a Buddhist text is usually looking at one of those additions rather than at a native letter. In the traditional recitation the two sibilants stand next to each other, which reflects both their sound and their shared descent from a pair of letters that were already adjacent in the alphabets Mongolian inherited from.