A simple preposition is a one-word preposition. A preposition can also come in a two-word or a three-word combination, which is called a compound preposition. A compound preposition functions as a single preposition. It consists of two words such as according to, because of, different from, due to, and instead of. Examples of three-word compound prepositions are as far as, in addition to, in front of, and in spite of.
There are words that are used only as prepositons as shown in the following table.
Two-word compound prepositions:
Three-word compound prepositions