One may assume a common origin of prepositions and verbal prefixes. The problems are associated with the relations among homonymous particles which have already become the subject of a quite voluminous literature, as far as their history and modernity are concerned. This study focuses on the doubling of these elements in syntactic structures such as przeszedł przez most ‘he went through the bridge’. The author suggests examining the relations in Polish from a slightly different perspective. The relations between particles are genetic i.e. being associated with their origin but one may also discuss the development of secondary relations. In the previous studies, greater attention is devoted to the duplication of a prefix by a preposition (dojść matki > dojść do matki ‘to reach [one’s] mother’. One of the problems which should be examined in a more comprehensive manner has to do with a reverse situation: the influence of the form of the preposition upon the form of the prefixed verb, cf. zaręczyć < ręczyć za ‘to vouch for’ +Acc.