If you ask me, all prepositional phrases are ultimately adverbial. What may seem uncomfortable is that we have to supply the words that are "ellipsised." And the words to be supplied are meant to clarify that more (not too much more) ambiguous prep phrase. But this is only the case at the surface level.
I really am not quite following the idea that a prep phrase can function as an adjective. This is quite foreign to my thinking. When we see a prep phrase as adjectival, I think we are looking at the surface level, rather than revealing the deep level structure.
Is there a "sure enough" prep phrase in the GNT that functions adjectivally? I just don't believe one can be produced at the deep structure level.
Am I looney?
