Intransitive and prepositional verbs

To give you some context, I'm reading Michael Swan's 'Practical English Usage', and I'm at a section covering passive voice and verbs with prepositions in the passive.

The author states that "The object of prepositional verbs can become subjects in passive structures." He then gives the example of "Somebody has paid for your meal" transformed into "Your meal has been paid for."

My question is: In this case, is "pay" an intransitive verb of incomplete predication and "for your meal" the subjective complement, and Swan is instead analyzing it as "pay for" being a prepositional verb whose direct object is "your meal", are both analyses correct, or am I missing something?

Answer

I do not see how "meal" can possibly be a subject complement because the person paying is not a meal.

The analysis given by Swan strikes me as sensible: "pay for" is considered a transitive verb and can be put into the passive voice like any transitive verb even though it is a prepositional verb.

It is perhaps not a perfect example because you might make the argument that the verb "pay for" is not an independent verb and is instead an ellipsis

Someone paid for your meal

is an ellipsis for

Someone paid the amount due for your meal

If we interpret the first sentence as an abbreviated form of the second, it becomes even more obvious that "for your meal" is not refering to the person paying; instead it is a prepositional phrase modifying the object, whether that object is explicit or implicit.

Personally, I see no reason to analyze the sentence as an ellipsis. I accept "pay for" as a legitimate prepositional verb (probably developed through an historical process of ellipsis because it does not seem to be what is called in German a seperable verb).

And whether or not "pay for" is a legitimate prepositional verb, both sentences can be put into the passive voice.

Your meal was paid for

or

The amount due for your meal was paid for.

In any case, Swan's main point does not depend on this specific example. All transitive verbs, whether or not prepositional, can be put into the passive.