Why a bed can be slept in but not under. Variation in passive V+P constructions

In English the verbs that collocate with prepositions are called prepositional verbs (V+P) and are often subsumed under the class of phrasal verbs (V+ particle) although they should be kept distinct: in fact, it is easy to show that prepositions and particles have different syntactic behaviors. One of the most striking characteristics of these verbs is that they can passivize, i.e. the prepositional object can be extracted from inside the PP and become the subject of the corresponding passive sentence. Not all prepositional verbs have a passive counterpart, though. Why? This paper addresses this question by regarding the prepositions entering (V+P) as functional elements, especially in view of their relationship with (“prepositional”) objects.