Mongolian Oe: The Rounded Front Vowel

Oe is the transliteration used here for the rounded front vowel, the sound usually written o with an umlaut in scholarly transcription, and it stands sixth in the alphabet. It belongs to the front class of the vowel harmony, and it is the front partner of the rounded back vowel written o. Like that vowel, it shares its written shape entirely with the letter that follows it, so that the two rounded front vowels are as indistinguishable on the page as the two rounded back vowels are. The script therefore has two rounded shapes for four rounded vowels, one shape serving the back pair and one serving the front pair, and each shape is resolved by the reader. That arrangement is more orderly than it first appears.

Because the harmony class of a word is fixed, a reader who has identified the word as a front class word already knows the rounded shape in it must be one of the front pair, so the ambiguity is halved before the reader has done any work at all. What remains is the choice within the pair, which the vocabulary settles. Unicode encodes this letter at U+1825. Alphabet charts that arrange the vowels by class rather than by recitation order place it directly beneath its back class partner, which makes the pattern easier to see than the recited sequence does.