The Kazakh Arabic alphabet contains 29 letters and one digit, the 'upper hamza' used at the beginnings of words to create front vowels throughout the word. The direction the alphabet is written in is right to left. Unlike the original Arabic script, which is an abjad, the Kazakh Arabic script functions more like a true alphabet, as each sound has its own letter and every sound in each word is spelt out in the written form of the language. The reform of the Arabic script from an abjad to an alphabet was carried out by the early 20th-century linguist Akhmet Baitursynov.