Inspection and Debate on Problems Concerning the Meaning of "Jiao"and the Wordforming of "Shuijiao

There are many arguments about the meaning of jiao and the time of the wordforming of shuijiao. According to a large number of our inspection,the usage of verb-measure word of jiaohas emerged greatly in the Middle Tang Dynasty. A few of examples of the word shuijiao have been found in the Late Tang Dynasty. The word is not a pianyi compound word. It is a word composed by two synonymous morphemes.jiaohas extended the meaning of sleep from wake up in the Tang Dynasty at the latest.