On the phonological reduction and diffusion of the nominative case particle no in Old Japanese

This study aims to explain the process of diffusion of nominative case marking in Old Japanese. The head-internal relative clause construction in OJ can be analyzed to have developed from the relative clause with DP construction preceding it. The particle no which appeared in the head position of DP changed from a genitive case marker to a nominative case marker as below:
　[_DP[_NP ][_D’ [no… [ ] … ]]] → [_DP [_TP[_DP … no][_T’ … ]]…]
This schema means that OJ had partial head-initial constructions before this change occurred.
The accentual data on OJ indicates that the case particles had their own accentual tones, as with substantial words. The phonological reduction of no was caused by the reanalysis of the DP structure in OJ.