Mongolian Ra ᠷ

Ra writes the trilled or tapped r and is the twenty-third letter of the alphabet. Like the velar nasal, it carries a restriction rather than an alternation: no native Mongolian word begins with it, so a word starting with r is a borrowing. The restriction is shared with Turkic languages and is one of the features often cited in discussions of what the languages of the region have in common.

Unicode encodes ra at U+1837. Inside and at the end of words the sound is entirely ordinary and common, so the constraint is narrowly about the initial position rather than about the sound at large. For a reader the letter is a useful signal. An initial r on a Mongolian page points to Tibetan, Sanskrit, Chinese or Russian vocabulary, and in a Buddhist text it points to the first of those two. Speakers of languages with this restriction commonly deal with borrowed words by adding a vowel in front of the r or by altering the consonant, and older layers of loanwords in Mongolian show such adjustments while newer ones increasingly do not, which is one of the ways a borrowing can be dated roughly by its shape. The letter itself is plainly written and carries no harmony alternation and no shared shape, so it is one of the shapes a reader identifies without effort. What it demands is knowledge of the lexicon rather than of the script: the letter is easy, and the inference a reader draws from finding it at the head of a word is where the real information lies.

An alphabet is a theory of a language, and reading it as one is instructive. The Mongolian alphabet says that this language has seven vowels sorted into two harmony classes with one neutral member; that its velars alternate with the class of the word; that it does not begin words with a trill, a velar nasal or a voiceless bilabial stop; that the difference between the members of certain consonant pairs is recoverable from context; and that it needs no letters at all for a set of sounds common in the languages around it. Every one of those statements is a claim about Mongolian, and the script commits to all of them. Where a claim turned out to be inadequate the alphabet was extended rather than rebuilt, which is why ten letters for foreign sounds sit at its end and a further apparatus for Sanskrit and Tibetan sits beyond that.

The clean way to read a borrowed script is therefore in two layers: what the source alphabet supplied, and what the borrowing language had to add. In Mongolian both layers are visible in the recited order itself, the inherited core first and the additions after it, so the alphabet is its own history lesson if you know where the seam falls. The reading has limits worth stating. A script records the sound system its users believed they had, at the moment the spelling was fixed, and traditional Mongolian spelling was fixed centuries before the modern spoken language, so the theory the alphabet states is a historical one rather than a current one.