vulg. dal, The tenth letter of the Turkish and Persian alphabets, and the eighth of the Arabian letters; its phonetic value is that of the letter d. Its numerical value is four. To distinguish it from the letter ذ the letter, د is called دال مهملە the neglected or undotted د , or ابجد the د of the word ابجد.This letter, like a few others, cannot be joined, in writing, to the letter which follows it, though it may be, joined to a preceding letter.In a few Arabic derived words of the eighth form (افتعالl), when the initialroot letter is د, ذ, or ز, the formative ت is changed into د, and this is made to coalesce with the initial radical in a letter د reduplicated in pronunciation; (in the case of initial ذ or ز , the reduplicated letter is sometimes ذ or ز , and sometimes the letters are written apart as pronounced) as ادعا iddiâ, and ادتعا idtiâ, for اذدكار izdikâr, for اذتكار iztikâr, and ازدواج izdivac for ازتواج iztivac.In Turkish words, the letter د is found occasionally where otherwise a ت or a ط, is used, as, تابولغە or دابولغا or خارلتی or خارلدی , خویرات or خویراد , etc. An originally quiescent final ت also may change into د which becomes movent; as, قورت a wolf, قوردڭ of a wolf, etc. Also in verbs; as, ایت do thou, ایدیڭز do ye, ایدر he does, he will do. In the word درت four, we have دردڭ of four, etc., but this rule of final quiescent ت changing into د is not generally applied fo monosyllables; e. g., آت a horse, آتڭ of a horse, etc. Where the medial remains quiescent it does not change into د ; as: قورتدە in a.wolf, قورتدن from a wolf; ایتدی he did, etc.Grammatically, the letter د fills three or four important functions in Turkish verbs. As an element of the causative syllable در (dir, dır, dür, dur), it helps to form the major class of causative verbs, as: یازدر make or let (it) be written, سوردر make or let (it) to be driven away or rubbed in; etc. When movent with esere, and followed or not by a vowel ی , it forms the perfect tense of the verb; and, followed by ق or ك , it forms the perfect active and perfect passive participles, as well as the perfect verbal noun; thus; یازدی he wrote; یازدق who has written, which was written; the past action of writing. When movent with üstün, and followed by a vowel ہ, it forms, the locative suffix or preposition (or postposition) دە (de, da) in or at; as; اودە in the house, at home. Again, movent with üstün, but followed by ن , it forms the ablative suffix دن from, than; as; بندن etc. The letter د is reduplicated in pronunciation instead of the ل of an Arabic definite article preceding it; thus الدعا ed-dü‘â.