Nov 9, 2013
One type of vowel derivative is the double vowel, which is known in Arabic as tanwiin تنوين .The process of tanwiin is a fairly simple one: Basically, you take a main vowel and place the same vowel right next to it, thus creating two vowels, or a double vowel. The sound that the double vowel makes depends on the main vowel that's doubled:
Double fatHa: تنوين الفتح tanwiin al-fatH: creats the "an" sound: حسناً 'Hasanaan.
Double dammah: تنوين الضمّ tanwiin al-dhamm: creates the "oun" sound: سيءٌ saiyoun.
Double kasra:تنوين الكسر tanwiin al-kassr: makes the "een" sound: حقيقةٍ 'Haqeqateen.