Arabic Vowel Rules (حركات)

Arabic uses short vowels (fatḥa, kaṣra, ḍamma) and long vowels (ā, ī, ū). Correct application is essential for morphology, pronunciation, and IPA generation. ACE applies vowel rules automatically based on your $infl1 / $infl2 selections and form patterns.

1. Short Vowels

Fatḥa ( ـَ ) — “a” sound
Kaṣra ( ـِ ) — “i” sound
Ḍamma ( ـُ ) — “u” sound

2. Long Vowels (Madd Letters)

Long vowels are produced by:

ا → ā
ي → ī
و → ū

ACE highlights long vowels in red and reflects them in IPA as /aː/, /iː/, /uː/.

3. Two-Vowel Pattern in Verbs

The imperfect verb uses two vowel slots: V1 (after r0) and V2 (after r1).

Example (root: ك ت ب):

V1 = a, V2 = u → يَكْتُبُ (yaktubu)
V1 = i, V2 = a → يِكْتَبَ (yiktaba) [dialectal or passive pattern]

4. Passive Vowel Rules

Passive forms use the pattern (u-i) in the past and (u-a) in the imperfect:

كُتِبَ → kutiba (he was written)
يُكْتَبُ → yuktabu (he is written)

5. Sukun Rules

A sukoon ( ْ ) means the consonant has no vowel. ACE inserts sukoon automatically between two adjacent consonants.

6. Tanwīn Rules

Tanwīn applies only to indefinite nouns and ACE omits it for verbs.

These rules govern all vowel rendering in Arabic & IPA output across ACE.