Devanagari letter ssa

In Sanskrit, ष is a curled-back “sh”-like sound.

It is a voiceless sibilant—an hissing consonant—made with the tongue tip curled toward the roof of the mouth. श is made farther forward, near the palate, while स is made near the teeth. English “sh” is only an approximation.

Many Hindi varieties pronounce ष like श. Sanskrit reading keeps the curled-back distinction. The language of the word is the cue: the letters can stay distinct in writing even when a Hindi speaker says the sounds alike.

How is ष different from श and स?

Sanskrit distinguishes them by where the tongue makes each sound.

श is palatal, made near the hard palate; ष is retroflex, with the tongue curled back; and स is dental, made near the teeth. The dots under ś and ṣ in Latin transliteration mark different Sanskrit sounds.

Sanskrit sandhi, where neighboring sounds influence one another, can turn s into ṣ after k, r, or vowels written a and ā in Sanskrit transliteration. A following t may then shift to retroflex ṭ. In इष्ट (Sanskrit iṣṭa), ष comes before ट, another retroflex consonant.

Where did ष come from?

It developed with Devanagari through regional forms of Brahmi.

Among the earliest substantial inscriptions in Brahmi are Ashoka’s edicts from the third century BCE. Sanskrit inscriptions in Brahmi date to the first century BCE. Proto-Nagari emerged toward the end of the sixth century CE, and Devanagari had become important for writing Sanskrit by the eleventh century.

Devanagari is an abugida: consonants normally carry an unwritten vowel, and a mark called virama suppresses it so consonants can join into clusters. Brahmi’s descendants include many Indic scripts. In क्ष (Sanskrit kṣa, often entered as ksha or ksh), क and ष join with a virama; fonts may show a fused conjunct, a half-form, or a visible virama.