Da is a letter of related and vertically oriented alphabets used to write Mongolic and Tungusic languages.
Mongolian language
Transcribes Chakhar ; Khalkha , and . Transliterated into Cyrillic with the letter . Syllable-initially indistinguishable from . When it must be distinguished from medially, it can be written twice, and with both medial forms (as in 'well', compared with 'holy'). Alternatively, a dot is sometimes used to the right of the letter in 19th and 20th century manuscripts. The belly-tooth-shaped form is used before consonants (syllable-final), the other before vowels. Derived from Old Uyghur taw (; initial, belly-tooth-shaped medial, and final) and lamedh (; other medial form). Positional variants on lamedh are used consistently for in foreign words. (As in / , / , or / ). Produced with using the Windows Mongolian keyboard layout. In the Mongolian Unicode block, comes after and before .