す, in hiragana, or ス in katakana is one of the Japanese kana, each of which represents one mora. Their shapes come from the kanji 寸 and 須, respectively. Both kana represent the sound [su͍]. In the Ainu language, the katakana ス can be written as small ㇲ to represent a final s, and is used to emphasize the pronunciation of [s] rather than the normal [ɕ] (represented in Ainu as ㇱ). * スィ and ズィ are also used to present si and zi pronunciations respectively. For example, 'C' is presented as スィー /siː/. See also Hepburn romanization.