S
the nineteenth letter of the English alphabet, is a consonant, and is often called a sibilant, from its hissing sound. It has two uses; one to express a mere hissing, as in Sabbath, sack, sin, this, thus; the other a vocal hissing, precisely like that of z, as in muse, wise, pronounced muze, wize. It generally has its hissing sound at the beginning of all proper English words, but in the middle and end of words its sound is to be known only by usage. In a few words it is silent, as in isle and viscount. See Principles of Pronunciation, §§ 90—94.