Word-initial glottal stops

The glottal stop is part of the consonant inventory of Arabic, and is particularly common in Cairene because the historical uvular stop qaf is realized as a glottal stop. These glottal stops are, naturally, explicitly represented in the orthography. Arabic exhibits pre-vocalic glottal stops at the beginning of words, also explicitly shown in text.

Word-initial glottal stops are predictable in Arabic; they occur, just as they do in English and many other languages, when the word starts with a vowel, except in ``weak'' environments that are also predictable. Although word-initial glottal stops were transcribed, they were collapsed with the following phoneme in the unit database. Because only a word-initial unit will be selected for a word-initial context in synthesis, a glottal stop is never inappropriately generated in a prevocalic context, and this binding reduces the size of the unit database.