Arabic Grammar - Phonology

Phonology

Classical Arabic has 28 consonantal phonemes, including two semi-vowels, which constitute the Arabic alphabet. It also has six vowel phonemes (three short vowels and three long vowels). These appear as various allophones, depending on the preceding consonant. Short vowels are not usually represented in written language, although they may be indicated with diacritics.

Hamzat al-waṣl (همزة الوصل), elidable hamza, is a phonetic object prefixed to the beginning of a word for ease of pronunciation, since literary Arabic doesn't allow consonant clusters at the beginning of a word. Elidable hamza drops out as a vocal, if a word is preceding it. This word will then produce an ending vocal, "helping vocal" to facilitate pronunciation. This short vocal may be, depending on the preceding vowel, ـَ a fatḥah (فتحة) /a/, ـِ a kasrah (كسرة) /i/ or ـُ a ḍammah (ضمة) /u/. If the preceding word ends in a sukūn (سكون) (i.e. not followed by a short vowel), the Hamzat al-waṣl assumes a kasrah /i/. Symbol ـّ šaddah (شدة) indicates a gemination or consonant doubling. See more in Tashkīl.