Mongolian Kha ᠻ

Kha writes an aspirated velar sound and is the twenty-eighth letter of the alphabet, the third of the ten added for foreign vocabulary. Unicode encodes it at U+183B. Mongolian does not distinguish aspirated from unaspirated consonants, so this letter records a contrast the language itself never makes, supplied for words in which the contrast matters in the language they came from. Sanskrit turns on exactly this distinction, pairing every stop with an aspirated partner, and Tibetan spelling preserves it; a Buddhist term written without it in Mongolian letters would be a different word in its own language.

The letter is therefore evidence about the seriousness of the translation effort. It would have been simpler to write the nearest Mongolian sound and let the reader manage, which is what happens to most loanwords in most languages, and the tradition declined to do so for this vocabulary. That decision runs through the whole extended apparatus: ten letters at the end of the alphabet for foreign sounds, and beyond them a further set of signs, encoded in Unicode under the name Ali Gali, for writing Sanskrit and Tibetan in full. The letter's shape is adapted from the velar that precedes it in the added group, following the script's general habit of modifying an existing form rather than inventing a new one, which is why the additions sit on the same spine and in the same hand as the inherited letters.

Adding a letter for a sound your language does not use raises a question that every transcription system has to answer: who is the letter for? A Mongolian reader with no Sanskrit will not pronounce an aspirated velar differently from a plain one, and for that reader the letter carries no sound at all. It carries spelling rather than pronunciation, which is a real and useful function. It preserves the shape of the source word, so that a term can be traced back, compared with its Tibetan or Sanskrit original, and distinguished from another term that would otherwise look identical.

Learned traditions across Buddhist Asia have made the same choice, and Japanese and Chinese Buddhist writing both preserve distinctions in the spelling of transcribed terms that ordinary speakers do not produce. The alternative is what happens to loanwords in daily speech, where the sounds of the receiving language take over completely and the origin becomes invisible within a generation or two. Mongolian Buddhist writing chose the learned route for its technical vocabulary and the ordinary route for everything else, which is why the added letters cluster in religious and administrative texts and are rare elsewhere.