Can you treat a prepositional phrase as the subject?

I just recently read this paragraph: "Think of an ad campaign that you still remember long after viewing it. Consider a book that might have inspired you. Behind those memories are solid writing."

I would say grammatically, the subject of that bolded sentence is "writing," and "behind those memories" is a prepositional phrase modifying "writing." Therefore, the verb would be "is" not "are" since it needs to agree with the subject. (solid writing, which is singular).

But even if it were changed to "Behind those memories is solid writing," I still find the sentence awkward. I am trying to figure out how I would reword, but perhaps, I am wrong, and it is fine as is.

Solution 1:

Yes, this is in fact possible, albeit rather unusual.

Q: May I call you later?

A: Sure, if it’s early.

Q: How early is early?

A: After ten would be too late.

In that final sentence, it’s most easily analyzed as the prepositional phrase acting as the grammatical subject of the verb be. You can swap the whole thing out as a syntactic constituent and replace with any more conventional subject without any trouble:

• He would be too late.
• Your call would be too late.
• Calling after ten would be too late.
• To delay even a little would be too late.
• For you to delay even a little would be too late.
• Whenever you called (it) would be too late.

Considering how interchangeable all those different types of subjects are in that sentence with the original “after ten”, we must conclude that prepositional phrases can sometimes serve as the syntactic subject or object of a sentence, not just as modifiers of nouns as verbs.

English is sometimes surprisingly flexible in its syntactic flexibility, and this one of those times.

Although there are ways to avoid this, these can themselves be unnatural if you aren’t careful. Most involve rearranging things and supplying a dummy it as the grammatical subject.

It would be too late for you to call me if it were after ten.