Classical Chinese lexicon is the lexicon of Classical Chinese, a language register marked by a vocabulary that greatly differs from the lexicon of modern vernacular Chinese. In terms of conciseness and compactness, Classical Chinese rarely uses words composed of two Chinese characters; nearly all words are of one syllable only. This stands directly in contrast with modern Chinese dialects, in which two-syllable words are extremely common. This phenomenon exists, in part, because polysyllabic words evolved in Chinese to disambiguate homophones that result from sound changes. This is similar to such phenomena in English as the pen–pin merger of many dialects in the American south: because the words "pin" and "pen" sound alike in such dialects of English, a certain degree of confusion can occ