Research on prepositional words and circumposition This subsection briefly summarizes the viewpoints of scholars and provides a comparative summary. On propositional frame. It refers to “a frame formed by a preposition in the front and other words at the back, with the object introduced by the proposition in the middle”. The expressive function of this frame is basically the same as that of the prepositional phrase. Propositions are the front part of propositional frames, and other words collocated with prepositions, such as nouns of locality, are the back part. On Circumposition. The subordinate concept of “adposition” is formed together with preposition, postposition and circumposition. He argued that circumpositions have at least three important features: firstly, the function of the whole frame is a prepositional; secondly, the whole frame is a closed structure such that both the structure and the number of prepositions and postpositions are closed; thirdly, circumpositions are not lexical items but a syntactic phenomenon, with different scopes for prepositions and postpositions.