Can a compound modifier include a verb or be a sentence?

Recently, my significant other and I were sharing our reactions to an image of someone who looked much older than they actually were on social media. We were texting each other.

I captioned the picture with ‘middle-aged-mum vibes’ (obviously, the noun phrase ‘middle-aged mum’ was pre-modifying ‘vibes’ here).

In jest, she responded with ‘[h]ad-a-kid-too-early vibes’.

I've taught my significant other about compound modifiers in the past, and I wasn't sure if this was in line with what I knew. I rarely saw compound modifiers with verbs in (and I don't really count gerunds in this case, since they technically function as nouns). I usually only see hyphenated compound modifiers with nouns, prepositions and co-ordinating conjunctions. I told her that I felt it would be a better option to use inverted commas instead.

I am curious as to whether a compound modifier with a word like an auxiliary verb is permissible, maybe even with a few examples. Some clarification would be much appreciated.

Solution 1:

Using an entire multiword phrase as an attributive modifier to the left of its noun is almost always an ad-hoc or nonce use that seldom gains sufficient popularity to enter into the annals of the lexicographers.

That’s at least in part because English strongly prefers having only light modifiers in the normal attributive position, not heavy ones. It prefers placing longer constituents like phrases and clauses to the right of their noun—and in the case of a copula, even farther to the right, off in the predicate after be.

That’s why you more often have a table in the kitchen than an in the kitchen table, or a species never before documented than you do a never before documented species. And sure, sometimes one like that last one may arise in writing. It doesn’t last long.

There’s no trouble coming up with versions of these that involve auxiliaries:

• When he opened the door, she saw he had a crestfallen, had been expecting someone else expression.
• She suddenly got a should have called first look on her face.

Those formulations are possible but awkward, and unlikely to gain popularity. Just please don’t call them unlikely to gain popularity expressions.

As for how you might best represent these spoken expressions using writing technology, it doesn’t much matter because they’re all super short lived flash in the pan one hit wonders doomed to fade away. And the sentence immediately preceding this one illustrates both why this should be as well as its simple remedy.

Personally I would probably use quotation marks not hyphens on the long ones. It looks messy enough as it is.