The preposition together with language elements accompanying it – the verb that substantively specifies the noun, which, in turn, dominates the preposition, in accordance with classical theory of word group, can, usually acting before the noun (only in some languages after it) fulfill grammatical or actual (spatial etc.) function.
•In current researches of preposition's behavior in language, attention is paid to their semantic function, with acceptance or negation of Jerzy Kuryłowicz's well-known thesis that the preposition is the main sub-morpheme of case.
Different semantic criteria primarily related to object localization or localization of events in place and time, are used for classification and determination of prepositions’ actual (semantic) functions. In addition, different prepositions can express causative, purposeful meanings or can be just indicators of temporal and spatial relations.
By accepting, primarily, the semantic criteria, more or less correct or sometimes only approximate classifications of all possible semantic relations and meanings of prepositions (prepositional expression) are determined.
In addition, preposition functions are often considered exclusively in the range of their closest contextual connections, but never in broader sense than their function of connecting the verb with the preposition and the noun or just the preposition with the noun. Such manner of analysis is sometimes prone to formulating insufficiently motivated theses on the semantic independence of prepositions. Thereto, all possible semantic fillings used in poetic language are excluded.
In elaborating the problem concerning prepositions, several criteria which serve to determine the said meanings of prepositions dominate. The type of prepositional construction meaning is decided by:
•Nominal context (type of connection with the noun),
•Verbal context (type of connection of the preposition with the verb),
•Both contexts together,
•Standpoint according to which, prepositions have semantic independence.
Most importantly, the preposition is placed in a sentence and together with independent (meaningful) expressions takes part in its construction. Accordingly, prepositions, similarly to case suffixes, take part in determination and establishment of the relations between expressions, parts of the sentence. However, majority of prepositions do not determine spatial and other relations existing in the real world totally unambiguously since a given relation can be built from several deferent prepositions or their combination.