Broadly speaking, prepositional idioms refer to the idiomatic use of prepositions after verbs, adjectives, verbal-nouns, etc, and with idiomatic phrases introduced by a preposition. Three striking differences exist between the idiomatic (prepositional idioms) and the unidiomatic uses of prepositions. The first is that while prepositional idioms have specific and clearly defined meanings (e.g. on hire, on fire, on duty, on pension, etc), unidiomatic prepositions have no very clearly defined meanings apart from the phrases or constructions in which they occur (e.g. sit on the bench and keep your pencil on the table or sit at the table). The second difference is that prepositional idioms are not always logical (e.g. averse…