Mongolian E: The Front Partner of A

E writes the open front vowel and stands second in the traditional order. It is the front class partner of a, and the pair is the clearest illustration of how Mongolian vowel harmony works: the vowels of the language sort into a back set and a front set, a word normally draws its vowels from one set only, and suffixes change their vowels to match the word they attach to. Inside a word, e is written exactly as a is written, with the same plain tooth on the spine, and nothing in the shape distinguishes them. The distinction is carried by the rest of the word. If the other vowels present belong to the back class the tooth is read as a, and if they belong to the front class it is read as e, so the harmony is not merely a phonological rule but a working part of the reading system. At the head of a word the two are separated, which is where the alphabet does mark them apart, and at the end each has its own trailing form.

Unicode encodes e at U+1821, immediately after a, preserving the order in which the alphabet is recited. A reader coming from a European alphabet should resist the assumption that an ambiguous letter is a defect. Scripts routinely leave to the reader what the language itself makes predictable, and Mongolian harmony is predictable enough that a fluent reader is rarely in doubt.