Scholars have attempted to reconstruct the
phonology of
Old Chinese from documentary evidence. Although the writing system does not describe sounds directly, shared
phonetic components of the most ancient
Chinese characters are believed to link words that were pronounced similarly at that time. The oldest surviving Chinese verse, in the
Classic of Poetry (
Shijing), shows which words rhymed in that period. Scholars have compared these bodies of contemporary evidence with the much later
Middle Chinese pronunciations listed in the
Qieyun rime dictionary published in 601 AD, though this falls short of a phonemic analysis. Supplementary evidence has been drawn from cognates in other
Sino-Tibetan languages and in
Min Chinese, which split off before the Middle Chinese period, Chinese transcriptions of foreign names, and early borrowings from and by neighbouring languages such as
Hmong–Mien,
Tai and
Tocharian languages.