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One On One or One-On-One: Grammar, Punctuation, Meaning, and Usage

Whether you are anticipating a private conversation or expecting a performance review at your place of employment, one-on-one meetings are a common part of everyday life. But you may be wondering why the phrase is hyphenated and what exactly it means. 

One-on-one should be hyphenated. When you use a compound or phrasal adjective before a noun, you should always hyphenate it to avoid ambiguity in meaning. The same is true for most numbers that are part of adjectival phrases. You can also write “one-on-one” as an adverb or a noun, and, in both cases, the phrase is also hyphenated.

When it comes to knowing when and where to add hyphens in American English, the waters can get a bit murky. But, when you are writing “one-on-one” — whether as an adjective, an adverb, or less commonly a noun — you’ll need those hyphens, even when it comes at the end of your sentence.  

Continue reading to learn more about what “one-on-one” means, how to use it correctly, and some other synonyms that you can use instead. 

What Does “One-On-One” Mean? 

Whether you are working full or part-time, chances are you’ll eventually have a one-on-one meeting with your boss or supervisor. 

And if you’ve played a sport at some point in your adolescent years, you may have even been matched one-on-one against a single player.

The three-word phrase can communicate multiple meanings (though all similar) depending on the context in which you use it. In the general sense, “one-on-one” means that you either discuss something with another person privately or compete against another person where no other players are involved (source).

One-on-One Meeting and Conversation Meanings

“One-on-one” is not limited to sports and employment, however. Rather, it includes any activity where two people speak directly to one another in a private setting or participate in a meeting or conversation without other people. 

This can include a conversation with a friend or spouse, a student and a teacher discussing a lesson, or even two children reading aloud to one another, one-on-one.  

There is not a significant distinction between a one-on-one meeting versus a one-on-one conversation. 

The former is likely a more formal, scheduled, or planned meeting where one person may be of a higher ranking than the other. The latter may be formal as well, but it refers to speaking or direct communication from one person to another, whether planned or in passing. 

Often, one-on-one conversations pertain to issues of disagreement, planning, or privacy.  

To determine the correct phrase, consider whether the situation is one of increased formality or pertains to a job or employment.

You can choose “one-on-one meeting” if there is a planned time and location involved, especially with a person who may be of higher ranking than yourself. But, generally, you’ll choose a “one-on-one conversation” if you are referring to a situation where you’ll simply need to talk to someone directly and privately. 

One-On-One Exchange Meaning

A one-on-one exchange isn’t much different from a one-on-one meeting or conversation. The meaning is the same in that the exchange or conversation occurs between two people, one-on-one. So you can assume that what you are exchanging is words, one to another. 

But, when you find the word “exchange” in this context, it often refers to money or some other tangible item, in which case you’d more often see and use the phrase “one-to-one” versus “one-on-one.”  Here is an example:

1.     There is rarely a one-to-one exchange rate between countries. 

An exchange rate refers to how much of one currency (money) you’ll need to buy a single unit of another currency (source). So, in this context, you’ll use “one-to-one” rather than “one-on-one.” 

We’ll take a look at more synonyms for “one-on-one” a bit further in this article. But first, we’ll break down the grammar and understand why the phrase requires hyphens.  

“One-On-One” Grammar and Usage 

As we mentioned earlier, “one-on-one” can act as an adjective, an adverb, or a noun. If you need a quick reminder, take a look at the chart below to refresh your understanding of these basic parts of speech.

AdjectivesWords that describe nouns — these can be single words, compound words, or adjectival phrases.
AdverbsAdverbs are words or phrases that describe how, when, where, or why something happens.
NounsNouns are people, places, things, or ideas. 

“One-On-One” – An Adjective

Adjectives are fairly simple parts of speech, given that their role is to describe nouns. Easy examples are colors, numbers, or other single words you can use to add detail and description to someone or something.

Compound adjectives are a bit trickier because rather than a single word, such as “green” or “beautiful,” compound adjectives contain two or more words that together function as a single adjective modifying a noun. 

Below are some examples of common compound adjectives:

  • Well-educated
  • Mouth-watering
  • Hard-to-find
  • Good-looking
  • Matter-of-fact

Most compound adjectives require hyphens so that your reader can clearly see that the two words, taken together, modify the noun that follows. 

Often, if the modifying adjective comes at the end of your sentence, hyphens are not necessary, but this isn’t always the case, and some use hyphens no matter where they appear in your sentence, as is the case for “one-on-one.”  

But the basic rule for hyphens and compound adjectives is that if there is any chance the meaning of your sentence will be misread or unclear, use hyphens (source). Here is a quick example:

1.     He carefully carried the three-foot tables off of the moving truck.  

2.     He carefully carried the three foot tables off of the moving truck. 

In the second sentence above, if we take the hyphen out of the compound adjective “three-foot,” a reader could easily assume that rather than showing the size of the tables, there were three distinct “foot tables.” Suffice to say, the hyphen is necessary for clarity here! 

There may be less ambiguity of meaning when it comes to “one-on-one,” but the rule still applies — it is a multi-word adjective where all three words are taken together as one compound adjective modifying a noun.  

Trigrams: A Three-Word Adjective

These types of three-word adjectives are “trigrams” — a group of three consecutive written letters, symbols, or words that together form a single thought or idea (source). Some are hyphenated only if you use them before the noun you are modifying, and others are hyphenated all of the time.  

“One-on-one” is simply an example of a trigram or compound adjective that uses hyphens all of the time.  

Examples: Using One-on-One as a Compound Adjective

You can use “one-on-one” either before or after the noun you intend to modify, though you will likely find that most use it prior to a noun

Let’s look at some examples:

1.     I have a one-on-one meeting with my boss at 4 p.m. today.

Here, “one-on-one” describes/modifies the noun (meeting) that the subject has with his/her/their boss. It is a private meeting that includes only these two participants. 

One-on-one describes the type of meeting, and, again, all three words are taken together as a unit. It is not a “one” meeting or an “on” meeting.

Here’s another example:

2.     The teacher prefers one-on-one conferences with her struggling students.  

In this sentence, “one-on-one” refers to the type of meeting the teacher is having — a meeting where she is able to speak directly and privately to her student who may need additional help with a lesson.  

You can also use one-on-one after a noun as a predicate adjective describing the subject.

3.     The competition between the two players was one-on-one.

Even though you are using the compound adjective at the end of the sentence, you should still retain the hyphens. This may sound confusing given that, earlier, we stated that compound adjectives that come at the end of your sentence do not necessarily always require hyphens.

As is the case with many English grammar rules, there is not always a clear and concise explanation. But, often, when a suggested “rule” becomes commonplace, we tend to adopt it as the norm, as is the case for “one-on-one.”

If you’d like to learn more about rules for hyphens, take a look at “High Quality or High-Quality: Understanding When to Use a Hyphen.”   

“One-On-One” – An Adverb

Generally, adverbs modify or describe a verb, though they can also modify adjectives or other adverbs. In the case of “one-on-one,” you’ll most often find and use it as an adjective, but since it can describe “how” you do something, we’ll take a look at a few examples.

1.     The teacher prefers teaching one-on-one.

Above, “one-on-one” describes how the teacher prefers to teach. Since “teaching” is a verb (more specifically, an action word), one-on-one is an adverb modifying the verb. Here’s another example:

2.     The players seemed to compete one-on-one, though soccer is a team sport.

Here again, “one-on-one” is an adverb because it is modifying the verb “compete.”

One-On-One – A Noun

The least common way that you’ll find “one-on-one” is as a noun. You can use the phrase in this way to refer to a meeting where the word “meeting” is assumed rather than stated directly.  Here’s an example:

1.     I have my one-on-one in a few minutes.

Most would assume that one-on-one refers to meeting here, likely with a boss or supervisor. But, in general, the connotative meaning when “one-on-one” is part of a noun or noun phrase is that it pertains to a meeting, not a competition or casual conversation.  

Another way you’ll find “one-on-one” as a noun may be pertaining to a therapist or counseling session. For example, a doctor may state that they have a “one-on-one,” which means that, rather than a group session or a session in which there are multiple members, the meeting is between two people only. 

Image by PDPics via Pixabay

One-on-One: Common Synonyms 

There are a few different synonyms that you can use for “one-on-one,” some of which also require hyphens and others that do not. 

The best thing you can do to make sure you correctly write these types of phrases is to consult a dictionary. You won’t go wrong in that way, especially since even native English speakers sometimes make these common mistakes.

Below you’ll find a list of common synonyms for “one-on-one.” Remember that synonyms are words that have the same meaning — or a very close meaning — to another word or phrase (source).  

Synonyms can be tricky, however. Oftentimes, one phrase works in the context in which you are writing, while a close synonym with a very similar definition does not connotatively make sense. 

This can be the case for “one-on-one” versus “one-to-one.” As we mentioned earlier, these two phrases are pretty similar, but their meanings are not the same in every context — there are situations in which you can use them interchangeably, but not always. 

“One-on-one” makes more sense for meetings, discussions, and correspondence, while “one-to-one” is more often applicable to mathematical functions, data, numbers, or relationships. 

More Synonyms for “One-on-One”

Both “person-to-person” and “face-to-face” are synonyms for “one-on-one,” but they don’t necessarily require a private meeting or conversation between two participants. 

  • Person-to-Person 
  • Face-to-Face

With these phrases, you can easily have two or even more people involved. Both refer more to situations when discussions should occur in-person versus over the phone or via email communication.

  • Head-to-Head

“Head-to-head” is another synonym that you can use, but this pertains to sports or other competitions when two players are competing against one another. You may also hear the phrase “toe-to-toe” or “man-to-man” in this context.

  • Eye-to-Eye

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Eye-to-eye is a synonym that connotatively assumes a disagreement between two people who cannot seem to find common ground with another. 

So, for example, you would use this phrasing for a meeting or conversation that includes two people who are in the midst of a disagreement and cannot see “eye-to-eye” regarding a particular subject.

Final Thoughts 

Phrases like “one-on-one” are complicated for many reasons — there are different ways to comprehend the term based on context, and the spelling is nuanced in that it requires hyphens as a compound adjective or trigram.  

Just remember that you really cannot go wrong retaining the hyphens if you are uncertain.  But, a good rule to follow is that if a compound adjective comes before a noun, use hyphens. If you are using it after the noun, check your dictionary to be sure, and while you are there, make sure that the phrase you are using has a corresponding connotation with your intended meaning and context.