Avestan Uu: The Letter in the Avestan Alphabet

This letter writes the long close back u and closes the vowel section of the alphabet. After it the consonants begin, and the shape of the sequence, vowels first and in pairs, has by then been stated eight times over. Every vowel in this alphabet is a letter in its own right, standing on the line and taking its turn between the consonants. That is not how the writing it grew out of worked, where a reader supplied much of the vowelling from knowledge of the word, and it is not how the Indic scripts of the same centuries worked either, where vowels hung as marks above and below a consonant sign.

Avestan writes them out. It stands sixteenth in the alphabet as a whole and sixteenth of the sixteen vowel letters, between Avestan U and Avestan Ke. The order is the work of the people who devised the alphabet rather than an inheritance from anywhere, and reading the list straight through recovers the analysis they were working from. Comparison makes the point quickly. Book Pahlavi, the hand this alphabet was drawn from, had let so many sounds converge on shared shapes that reading it depends heavily on already knowing the word. The Avestan alphabet takes that apart and assigns one sign to each sound, which is why it needs fifty-four of them.