When is 'off guard' hyphenated?
Hyphen is required when phrasal adjective comes before the noun it modifies. For an example,
In the sentence, "Man-eating shark" man-eating is a phrasal adjective modifying the noun shark. This sentence means a shark that eats a man. Now, if you remove the hyphen in "Man eating shark", then it means in some corner of the world some man likes to eat a shark.
So, it is apparent to use hyphen when phrasal adjective modifies noun. In that, you inform your reader explicitly that both the words act as a single unit.
And, if a compound word is not modifying any noun that it precedes, then we are not required to use hyphen or it is completely optional to use hyphen. Then, it becomes the matter of personal choice.
Now, let us consider the three specific instances in your book.
Instance 1:
“I wanted to find it before my opponents did,” he clarified. “So, if anything was brought up during one of the many townhall debates we had, I was ready to respond and defend myself instead of being caught off guard.”
Observation 1: Here, the compound word off guard is used in an idiom caught [sb] off guard. Here, the compound word off guard is not modifying any word. So, we are not required to use the hyphen.
Instance 2:
In hindsight, this was a fatal mistake, as Superior Holt caught us off guard and alone in the vestibule as we were attempting to leave.
Observation 2: Again, the compound word off guard is not modifying any word. So, the hyphen is not required.
Instance 3:
The lack of context to his question caught me off guard.
Observation 3: Again, in the idiom caught [sb] off guard off guard is not modifying any word. So, you are not required to you the hyphen.
American Dictionaries
One that support compound word off guard without hyphen:
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Merriam Webster [check under entry 6 b]
Example sentence from M-W: "Her angry response caught me off guard."
Here, if you observe, then the compound word off guard is not modifying any noun. So, M-W prefers to use unhyphenated compound word. It is a matter of preference.
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Dictionary.com [check under idioms, you have to scroll little bit]
Example sentence from Dictionary.com: "The blow from behind caught him off guard."
Here, again off guard is not modifying any noun.
One that support compound word off-guard with hyphen:
- The American Heritage https://ahdictionary.com/word/search.html?q=off%20guard
Example from The American Heritage Dictionary: "a quiz that caught the class off-guard"
Here, the American Heritage Dictionary prefers to use the hyphenated compound word off-guard even though it is not modifying any noun. If you use, unhyphenated off guard in same example. The meaning or the intention of the sentence will not change. It is a matter of choice of The American Heritage Dictionary.
British Dictionaries: I am not taking liberty to explain further. I guess, I have covered the explanation in detail.
One that support compound word off guard without hyphen:
Oxford Dictionary
Cambridge Dictionary
One that support compound word off-guard with hyphen:
- Macmillan Dictionary
- Collins Dictionary
- Longman
Google Books Ngram Viewer search suggest that usage of off guard is more popular than off-guard. In other words, there are few instances where off-guard modifies the noun it precedes or the author simply prefers to use hyphenated off-guard instead of unhyphenated one.
Blue is off guard and Red is off-guard.
The two most prominent U.S. dictionaries—Merriam-Webster and American Heritage—disagree on the hyphenation question. In its entry for guard, Merriam-Webster Online includes this subentry for "off guard":
off guard : in an unprepared or unsuspecting state {Her angry response caught me off guard.}
Merriam-Webster's Eleventh Collegiate Dictionary (2003) includes the same subentry for "off guard" except that it omits the "Her angry response" illustrative example.
The American Heritage Dictionary of the English Language, fifth edition (2010), on the other hand, has this entry for "off-guard":
off-guard adj. Off one's guard; unprepared: a quiz that caught the class off-guard.
In short, presented with the same syntactical situation, Merriam-Webster endorses the form with two words and no hyphen:
...caught me off guard.
and AHDEL endorses the form with a hyphen:
...caught the class off-guard.
So if you aren't already committed to following one of these dictionaries' style preferences across the board, it's up to you to decide which recommendation to follow. Just make sure that—once you've made your choice—you enforce it consistently throughout your manuscript.
Stylistically, hyphens tend to be used with compound adjectives forming a single idea that precede the noun they modify, but not with compound adjectives following a noun or adverbial phrases.
The Compound Adjective
The APA Style Guide has several rules for using hyphens, including this:
In a temporary compound that is used as an adjective before a noun, use a hyphen if the term can be misread or if the term expresses a single thought (i.e., all words together modify the noun).
Daily Writing Tips provides a decent representation of what may be recommended regarding hyphenation. Usually compound adjectives that follow a noun don't have a hyphen. If you think that "off guard" is an adjective, you're safe omitting the hyphen.
The Adverbial Phrase
However, in all three of your examples you may be using "off guard" as an adverbial (not an adjective) that modifies the verb "caught." (The Oxford English Dictionary classifies "off guard" with "catch," "take," and other verbs as an adverb.) "Off" introduces the phrase as a preposition. This usage is represented in idiomatic form by the Cambridge Dictionary as "catch (someone) off guard." In this reading, "off guard" describes the manner in which someone is caught, like "by surprise" or "unawares." Such adverbial phrases usually do not use a hyphen. It is possible that some writers overcorrect and introduce the hyphen as if it were a compound adjective, but again, you would be safe omitting it.
Unfortunately, I don't think that common principles of hyphenation establish a single correct way to punctuate "off guard" in your sentences. Fortunately, I think that either using or not using a hyphen would be defensible here. My preference would be to omit the hyphen in your sentences.
Prepositional phrases vs. compound adjectives
When the word off takes a noun (or rather, a noun phrase) as its object, it is usually analyzed as a preposition. Here is a clear example of the use of the preposition off: "The hotel was off the beaten path". Hyphens are not usually used after prepositions.
When a prepositional phrase is placed attributively before a noun, though, hyphenation between all words in the prepositional phrase is standard. Thus we write things like "an out-of-breath hiker" or "an out-of-tune piano", or even "an off-the-beaten-path hotel". Likewise, in the uncommon situation where "off-guard" is placed before a noun, it would be hyphenated: "an off-guard moment" or "an off-guard stance". One way to interpret phrases like this is to analyze the hyphenated segment as a "compound adjective" derived from the original prepositional phrase. (In general, prepositional phrases are not and do not behave the same way as adjectives.)
One book's recommendations
Edward D. Johnson's Handbook of Good English (1991) indicates that some compound adjectives derived from prepositional phrases "have become permanent compounds" and can even be used predicatively: Johnson's example is "off-the-wall" in the sentence "The report was off-the-wall" (p. 209). To figure out whether a particular prepositional phrase has an established usage as a compound adjective, Johnson seems to recommend taking one of the following three approaches: check a dictionary, trust your ear, or omit the hyphen.
Prepositional phrases that have not become permanent compounds are not hyphenated when the occur after the modified word, and omitting hyphens in a permanent-compound prepositional phrase is not really an error, since dictionaries differ in what they consider permanent compounds worth listing. If the compound word would be pronounced almost as one word rather than as separate words, it has a claim to being considered a permanent compound. Those who don't trust their ears can use a specific dictionary as an arbitrary authority, as many professional editors do.
(p. 209)
Applying this information to off guard
It's somewhat difficult to figure out the role of off guard in your example sentence, because different kinds of words can come after the verb caught.
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caught can be followed by a prepositional phrase, as in "caught in the middle" (or "caught right in the middle", where "right" is an adverb that characteristically modifies prepositional phrases)
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caught can be followed by an adjective, as in "caught unprepared"
If "off guard" in your sentences is a prepositional phrase, it should not be hyphenated. If it is a compound adjective, it could be hyphenated, but omitting the hyphen also seems to be OK. So I would recommend using a space and not a hyphen.
In off guard, the hyphen need only be used when the phrase stands in front of a noun it modifies (as an adjective in the attributive position), as in an off-guard supervisor. This is to distinguish the unaware supervisor from a man supervising guards, who is a bit weird, whom one might call an off guard-supervisor or an off guard supervisor (here the hyphen is unnecessary, since a noun is by default first associated with the adjective closest to it). In all of your examples, the hyphen would not avoid another default reading and need not be used. It could, perhaps, be used in the predicative position as well, for symmetry; but it is not as clearly necessary. I welcome comments on this last point.
It is not obvious whether off guard in your examples is to be classified as an adverb rather than a (predicative) adjective. But, if it is an adverb, a hyphen would apparently be no more warranted than a hyphen in at home.
For more detailed reasoning about hyphens (as opposed to statements of merely statistical fact and blind reliance on doubtful authority), see Fowler's A Dictionary of Modern English Usage.