"Exactly noon" parts of speech

Question

What are the parts of speech in this phrase?

exactly noon

Any dictionary will say that "exactly" is an adverb, and that "noon" is a noun, but I haven't heard of adverbs modifying nouns, so there's something fishy going on here.

My only faint hope is that "noon" might be some shadowy category like a determiner with a historically understood noun like "time", "hour" or "hours", but I can't find anything online to support this.

I'm looking for something that extends to all times of day, including "three o'clock" and "three twenty-five". I chose "noon" for simplicity.

Answer 1

I would still consider noon a noun (one that can by itself constitute an entire noun phrase/NP, so in this regard behaving more like a pronoun than like a regular noun such as day) in that context.

Related Linguistics SE post: Adverbs as NP pre-modifiers

In general, I believe many modern linguists consider it false to say that no adverb can modify a noun or noun phrase. (BillJ has left comments indicating that what's going on here is an adverb modifying a noun phrase.)

I found what looks like a relevant chapter "Adverbs, Noun Phrases, and Determiners" in the report A Lexicalized Tree Adjoining Grammar for English (The XTAG Research Group, Institute for Research in Cognitive Science, University of Pennsylvania, http://www.cis.upenn.edu/~xtag).

The authors state

Many adverbs interact with the noun phrase and determiner system in English. [...] Although there is some debate in the literature as to whether these should be classified as determiners or adverbs, we believe that these items that interact with the NP and determiner system are in fact adverbs.

They in fact list exactly, but describe it in a way that doesn't seem to account for the usage with noon that you asked about:

the class of adverbs that modify cardinal determiners. This class includes, among others, the adverbs about, at most, exactly, nearly, and only. These adverbs have the single restriction that they must adjoin to determiners that are card+.

Based on the description of determiner features in the chapter "Determiners and Noun Phrases", the class of "determiners that are card+" (or positive for the feature "cardinal") seems to consist only of cardinal numbers such as one, two, three.... All other determiners, such as all, both, this, the, a/an are shown as "card-" in the table on that page. This analysis does work for examples like "exactly three o'clock" and "exactly three twenty-five".

I think other examples to consider are "I ran exactly a mile", "At almost exactly the moment when...", "at exactly that second", "at exactly the moment", "at exactly this time". Most examples I can think of do use a determiner of some kind (although contrary to the chapter, they are not exclusively cardinal numbers) and you I guess could consider the adverb to be modifying the determiner rather than the noun phrase (although that feels a bit iffy to me with "exactly the").

Answer 2

It happened at exactly noon.

Adverbs can modify nouns, though the construction is subject to severe constraints. For example, A shortage of timber internationally led to an increase in prices, where the adverbial modifier is restricted to post-head position.

But adverbs freely modify NPs, and since "noon" is an NP consisting of just a noun, it is fine to say that "exactly" is modifying the NP "noon".

Consider also examples like: I like only fish, where the focusing adverb "only" is modifying the NP "fish". And He ate almost the whole pie, where the adverb "almost" is modifying the NP "the whole pie".

The times of day are NPs, so they too are freely modified by adverbs.

Answer 3

In everyday usage the adverb seems to be qualifying the verb to be, whether explicit or implied. The result is that we see what looks like a noun phrase.

Compare It is exactly noon with It is roughly noon
NP: exactly noon, roughly noon

The same usage applies to other verbs. Compare
It weighs exactly three grams with it weighs approximately three grams
NP: exactly three grams, approximately three grams

And it extends to the modifying of adjectives. Compare
the flower is entirely red with the flower is mainly red
Modified adjective: entirely red, mainly red

The adverb qualifies the state of being of the noun or of the instance of the adjective.

{I admit “Tentatively pragmatic, this is not exactly authority.”}