History of grammaticalization of"投"and related question

The original meaning of投isthrowverb.From the pre-Qin,many items extending from投have most- ly actived in the modern Chinese language in the written language or verbal.In the Eastern Han Dynasty,the meaning has become empty,and at the period of the Five Dynasties and Yuan Ming,the examples in which word was used as preposition were much more.But occasionally in the works in the Qing Dynasty,the examples almost disappear.This paper tries to in- spect its specific development paths,and make the preliminary explanation to its grammaticalization formation,the develop- ment and the evanishment reason.