s

s, nineteenth letter of the modern Latin alphabet. It corresponds to the Semitic sin “tooth.” The Greek treatment of the sibilants that occur in the Semitic alphabet is somewhat complicated. The Semitic samech appears in Greek as Ξ (xi) with the value in early times of /ss/, later and more generally of /x/ or /ks/. The name samech, however, which through its Aramaic form became in Greek Σ (sigma), was applied to the letter that corresponded to Semitic sin and stood for /s/. In certain Greek alphabets, the letter was called san. Semitic ssade appears in the early alphabets of Thera and Corinth in a form that represents /s/. These alphabets have no sigma, while those that have sigma do not have the Semitic ssade.

A rounded form appeared in the Chalcidian alphabet, and from this it was taken into Latin. Etruscan had no rounded form, but it appears in Umbrian and Faliscan. In England in the 17th century a looped form was introduced, and this is occasionally still seen in handwriting when followed by another s. There was a Greek minuscule form c of the 9th century ce, and this may be the source both of the Cyrillic c and of the lunate sigma used in some fonts of modern Greek type.

The letter represents an unvoiced sibilant. This has become voiced in English when intervocalic (e.g., in houses and nose). In most other positions, it remains unvoiced (e.g., in sing, save, speak, and aspect). When doubled, the letter represents the unvoiced sound in all positions (e.g., in grasses, miss, and assess). In vision and other words ending in -sion, the s, provided it is not doubled, has the voiced sound /zh/, and it has a similar sound in such words as pleasure and leisure.