Prepositions

A complex preposition is a word group (such as "along with" or "on account of") that functions like an ordinary one-word preposition. Complex prepositions can be divided into two groups: two-word units (a word + a simple preposition), such as apart from (also known as compound prepositions).

Conceptually, the double preposition is very similar to the compound preposition: both consist of two-word phrases. However, the double preposition is formulated through the conjunction of two simple prepositions—whereas the compound preposition is formulated through the conjunction of a non-prepositional word and a simple preposition.

In practice, the compound preposition tends to signify spatial relation, whereas the double preposition tends to signify movement.