Many prepositions we use are single words like in, on and at. These are called simple prepositions.
There are also prepositions which are made up of two or three words. These complex prepositions act in the same way as single-word prepositions.
Like simple prepositions, these two-word combinations come before a noun:
Examples: according to Shakespeare, contrary to my advice, due to illness, in aid of charity, in front of the window, in line with inflation.
Three-word combinations often have the following pattern:
Simple Preposition + Noun + Simple Preposition