Throughout East Asia, Literary Chinese was the language of administration and scholarship. Although Vietnam, Korea, and Japan each developed writing systems for their languages, these were limited to popular literature. Chinese remained the medium of formal writing until it was displaced by vernacular writing in the late 19th and early 20th centuries. Though they did not use Chinese for spoken communication, each country had its tradition of reading texts aloud, the so-called Sino-Xenic pronunciations, which provide clues to the pronunciation of Middle Chinese. Chinese words with these pronunciations were also borrowed extensively into the local vernaculars, and today comprise over half their vocabularies.