The form of the adposition plays a role as to whether or not it can be postposed. Prepositions such as də, with its CV structure, cannot be postposed. Only adpositions with at least CVC structure can be postposed: bash alb 'under tree' can become alb su bash 'under tree'. However, not all adpositions with CVC structure can be preposed, e.g. kadz su pɛrt 'near house' cannot be expressed as pɛrt kadz.
(See Clements 1996: 143–145.)
Source: Clements 2007: 171
Source: Clements 2007: 171
Source: Clements 2007: 171