Mongolian Cha: The Voiceless Affricate

Cha writes the voiceless palatal affricate, the sound English spells ch in church, and it is the twentieth letter of the alphabet. It is native, common and distinctly written, and with the voiced affricate that follows it it forms a pair on the same model as the sibilants and the stops. Unicode encodes cha at U+1834. The affricates entered Mongolian's ancestry from a letter that had originally written something else, which is the ordinary history of a borrowed alphabet: as a script passes from language to language, letters are reassigned to whatever the new language needs a sign for, and the sound a letter writes today may have little to do with the sound it was invented for.

The Aramaic abjad from which this script ultimately descends had no palatal affricate, and the sign that ended up carrying it in Mongolian did other work in earlier stages. A reader tracing correspondences between Mongolian and its Semitic ancestors should therefore expect the vowels and the plain consonants to line up cleanly and expect the affricates to be where the alignment breaks down. The letter is common in native vocabulary and also frequent in Tibetan loanwords, where it renders more than one source sound.