2.2.2 The object
Quite what determines when a prepositional object may undergo this movement and when it may not is not well understood. It seems to have something to do with the relationship between the verb that is passivised and the preposition whose object moves: the closer the relationship, the more likely the object will be able to move. Thus the at preposition in (65) is closely related to the verb, heading the PP complement of this verb. The near preposition in (66) does not head a PP complement, but a PP that modifies the verb. Modification is not such a close relationship as it is not indicated in a head’s lexical entry, but can be fairly freely be added to any appropriate head.