This paper develops a syntactic classification of Polish synsyntagmatic elements (i.e. lexical items which cannot occur in syntactic structures by themselves, such as complementizers, relative pronouns, co-ordinators, etc.) based on their order in syntactic structures. The problem of the word order and related problems are discussed from the perspective of the methodology of descriptive grammar. The study discusses ten classes of synsyntagmatic elements distinguished in the general classification and offers a preliminary account of their syntactic properties. The main conclusions are: (l) the majority of synsyntagmatic elements precede the elements they co-occur with, (2) co-ordinators appear between they elements they join, (3) only sentential operators do not have a fixed position, and (4) the order of particles proper is determined syntactically and semantically and is subject to prosodic principles.