S's the nineteenth letter in the modern Latin alphabet. Its name in English 's spelled ess, or usually es- when part of a compound word; the plural's esses. S's pronounced /s/ in most languages, though it's also commonly pronounced /z/ (as in the Portuguese mesa, the English does, or the German sein), or occasionally /ʃ/ (as in the Portuguese botas in the Carioca accent or as Hungarian kis). History Proto-Semitic š Phoenician S Etruscan S Greek Sigma Semitic Šî… (More on S)