Nunation

Nunation
Symbol

ٍّ
ّ
Transliteration
-un
-in
-an
Nunation (the Arabic term is تنوين , tanwīn) is the addition of a final -n to a noun or adjective. The vowel before it indicates grammatical case. In written Arabic nunation is indicated by doubling the vowel diacritic at the end of the word. There are three of these vowel diacritics, and the signs indicate, from left to right, the endings -un (nominative case), -an (accusative), and -in (genitive). The sign  is most commonly written in combination with ا ʼalif ( ا ), ة (tāʼ marbūṭa تاء مربوطة ) or stand-alone ء (hamza همزة ). An alif should always be written unless the word ends in tāʼ marbūṭa, hamza or is a diptote, even though the -un, -an, or -in is not written. Nunation is used only in formal Arabic (including Modern Standard Arabic); it is absent in everyday spoken Arabic, and many Arabic textbooks introduce even standard Arabic without these endings.