i and dotless
ı are distinct letters in the Latin alphabets of a number of Turkic languages including Turkish, Azerbaijani, and Kazakh, unlike English and most languages using the Latin script, where the capital letter I is dotless (I) while the lowercase letter I has a dot on it (i). They are also used by the common Turkic Alphabet:
- Dotless I, I ı, usually denotes the close back unrounded vowel sound (/ɯ/). Neither the upper nor the lower case version has a dot.
- Dotted İ, İ i, usually denotes the close front unrounded vowel sound (/i/). Both the upper and lower case versions have a dot.
- İstanbul /isˈtanbuɫ/ is the Turkish spelling for Istanbul. It starts with an i sound in standard dialect of Turkish, not an ı.
- Diyarbakır /diˈjaɾbakɯɾ/ is the Turkish spelling for Diyarbakir. In Turkish the first and last vowels are spelled and pronounced differently.
- Bakı /bɑˈcɯ/ is the Azerbaijani spelling for Baku.
In contrast, the letter j never has this distinction in these languages, with a dot in the lower case character: J j, but the dotless j does exist in Unicode: ȷ. That letter is sometimes used in mathematics with a combining hat to indicate a unit vector.