In traditional grammar, the term “preposition” is used to refer to a class of words that express a relationship in space or time or mark various grammatical or semantic roles. For example, “with me”, “on the table” and “in March”. In all of these examples, prepositions come before the words they govern. That is why they are called pre-position (i.e. positioned before).

There are prepositions that come after or around the word they govern. For example, in Latin “mecum” (with me), the preposition “cum” comes after the pronoun “me”. That is, in Latin they say “me with”. In Japanese, they say "the table on" and "the bank to". In Persian, the object of the sentence is marked with the preposition را (râ) placed after the word or words it governs. In classical Persian, there are prepositions that have two parts: one coming before and the other coming after the words they govern. For example, “مر او را” (mar u râ).

To differentiate between the different types of prepositions, in modern grammar, the term preposition is exclusively used for the type that comes before the words they govern. Those that are positioned after called postpositions and those that come around the words they govern, are called circumpositions. The term adposition is a collective name for prepositions, postpositions, circumpositions and all the other types that may exist.