Tibetan Greng Bu ◌ེ

Greng bu is the third of the four Tibetan vowel signs and writes the vowel e. It sits above the consonant it modifies, as gi gu and na ro do, and replaces that consonant inherent a, so ka with greng bu upon it is read ke.

The name is read in the grammatical tradition as the upright or standing one, from a verb meaning to stand, which describes the shape of the mark. That is a transparent gloss and the tradition offers it consistently, which is not the case for all four names.

Like the other signs it is dependent and cannot stand alone. Where a syllable begins with e the sign is written on a chen, the thirtieth consonant, and shown by itself it is displayed on a dotted circle.

Tibetan does not distinguish vowel length in its own vocabulary, so there is no long e to write and no sign for one. What exists instead is a device for foreign words, taken up in the article beside this one.

Greng bu is recited third of the four, after gi gu and zhabs kyu and before na ro, and the same sequence is used when Tibetan words are sorted, so the position of a sign in the recitation is also its position in a dictionary.

As with every Tibetan vowel, the sound produced for a syllable containing greng bu depends on what follows it. A suffix reshapes the vowel in front of it, so the value of the sign is settled only when the end of the syllable has been reached, and the sign on its own does not tell a reader what will be heard.

Sanskrit distinguishes long vowels from short ones and the distinction is meaningful, so a Tibetan translator writing a Sanskrit name or a mantra could not simply ignore it. Tibetan has no vowel length of its own and its four signs make no provision for one.

The solution was to extend the signs rather than to invent new ones. A doubled vowel sign writes the long vowel: two greng bu for a long e, two na ro for a long o, and the same principle for i and u. For the long a, which has no sign of its own to double because a is the inherent vowel, the small a is subjoined beneath the letter instead.

This belongs to the same body of machinery as the reversed letters and the subjoined ha: a set of devices built beside the alphabet so that Sanskrit could be written exactly, without disturbing the thirty letters and four signs that a Tibetan child recites. All of it is taught after the alphabet and to a narrower group, and a reader of ordinary Tibetan may never need any of it.

The general shape of the solution is characteristic of the script. Where something new is needed, an existing element is modified, doubled, reversed or subjoined. Nothing is imported whole.

None of it changed the recitation. A Tibetan child still learns four vowel signs and thirty letters, and the long forms are taught later, with the rest of the transcription apparatus, to those who will have to read Sanskrit.