The matter of long vowels in Turkish started in the second half of the 19th century with the work of Böhtlingk which is called Die Scprahen Der Jakuten. After he discovered long vowels in Jakutisch (Saha) many researchers such as Radloff, Karl Foy, Gronbech claimed different things which some of them supported the existence of long vowels in Turkish while some of them tried to disclaim the issue. Dıvānu Lugatı’t Turk which is one of Arabic lettered Turkish manuscripts written in the 11th century was studied by Polivanov in terms of long in vowels in Arabic lettered Turkish manuscripts. His work led to open a way in this field. In Kıtābu’l Idrāk Lı-Lisānı’l Atrāk, written in order to teach Turkish to Arabic people in the 14th century by Abu Hayyan in Egypt, some of Turkish words which invovels long vowel were written differently than the other words which do not include long vowels. On this occasion, Abu Hayyan used some letters (ا، و، ي) which are called huruf-u med to try to indicate the long vowels. In this study, long voweled Turkish words were identified in Kıtābu’l Idrāk Lı-Lisānı’l Atrāk and then those words were compared with Dıvānu Lugatı’t Turk and other Arabic lettered Turkish manucripts which were written in Mamluk-Kıpchak era/area. In this way, we tried to demonstrate the similarities and discrepancies between both Kıtābu’l Idrāk Lı-Lisānı’l Atrāk and other manuscripts. Also, these words were exemplified from modern Turkic languages such as Turkmenish and Jakutisch.
Kıtābu’l Idrāk Lı-Lisānı’l Atrāk, Long Vowel(s), Arabi Lettered Turkish Manuscripts.