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Comma after “oh”: Here’s When You (Don’t) Need One

Comma after “oh”: Here’s When You (Don’t) Need One

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When to put a comma after “Oh” in a sentence
Oh, hi!

Didn’t see you there.

Were you looking for an article about comma use after the word “oh”?

If so, I have just the thing.


Do you need a comma after “Oh”?

When you’re using “Oh” like an interjection (a part of speech used to express surprise or to interrupt someone), it is not really connected to any other part of the sentence, so you can think of it as being a nonessential phrase.

So far as commas go, that means that you should put a comma after the word “oh” to separate it from the rest of the sentence.

If you want to show extreme surprise, you can use a period or exclamation mark instead.

Additionally, if the word “oh” is at the end of a section of written dialogue, remember that the comma should go inside the quotation marks.

Note that it’s possible for “oh” to be part of a longer interjection like “Oh no” or part of an adverbial phrase like “oh so quiet,” in which case a comma is not used.


Using “Oh” in a sentence

“Oh” is basically just verbal filler, although it can be useful to show thoughtfulness or surprise.

Used in this way, “Oh” is a type of word called an interjection.

Basically, it’s a way to interrupt the normal flow of a sentence if something unusual happens or if you suddenly remember something else you need to say.

The comma rules for using “Oh” like this are pretty simple.

Because “oh,” like any other interjection, is not essential to the meaning of a sentence, it needs to be set off everything else. That’s accomplished with one or more commas.

“Oh” almost always appears at the beginning of a sentence, so to set it off from everything else you need to place a comma after it.

If “oh” appears in the middle of a sentence, then another comma also needs to appear in front of the word.



“Oh, I didn’t see you there.”

“Really? Oh, I hadn’t thought about it like that before.”

“I’ll see you in, oh, an hour or so.”

The first two examples show how the word “oh” starts a sentence, and is then separated from the remainder by a comma after it.

In the third, “oh” appears later in the sentence, so in addition to the comma which follows the word we need one before it.

All of these are great examples of why “oh” is not an essential word. If you remove it from the sentence, the meaning doesn’t change at all.


Expressing greater surprise with “Oh!”

Sometimes, a humble comma isn’t enough to express yourself or your characters in writing, you can consider separating “oh” even more forcefully by using a period or even an exclamation mark.

Because a lot of the meaning in a word like “oh” is implied, people might take a written “oh” with a comma after it as an expression of disappointment or even sarcasm in some cases.

Just think of the phrase “Oh, really?” used by someone in an argument with a loved one.

An exclamation mark after “oh” instead of a comma makes the word really stand out, and can in some contexts help show excitement rather than disgust.

Even if the meaning of the word might not be misinterpreted, an exclamation mark will make your reader sit up and pay attention in a way a comma won’t.



“Oh! That reminds me of a book I read recently.”

“We need to get going. Oh! Don’t let me forget to stop at the store on the way home later.”


In the first of these examples, using a comma might come across as dismissive in a written setting such as a text message by phone.

By using an exclamation mark, the “Oh!” makes it clear the author is remembering something they’re excited by.

In the second example, the exclamation mark suggests that the speaker has very suddenly been reminded about something they don’t want to forget.


Using “Oh” in written dialogue

Words like “oh” should probably not be used in a formal setting such as a school paper or an official report.

That’s because “oh,” like other interjections, is a grammatically meaningless phrase used primarily to express some kind of emotion.

In formal writing, neutrality is more often praised, and even if you’re trying to evoke emotion you will probably use different techniques, such as effective choice of adjectives and adverbs or through the types of argument you employ.

One place you might need this word in writing, however, is if you’re writing dialogue, or the words spoken by fictional characters in a story or play.

The comma rules for dialogue are much the same as for regular writing, so there are no new rules to learn on that front.

However, dialogue is typically placed in quotation marks.

Any time you have quotation marks in a sentence, you should place the comma inside them rather than outside them. (Note: This is different in UK English, which places punctuation like commas outside of quotation marks.)



“Oh,” she said. “Is that right?”

“Oh,” sang the camper, “give me a home where the buffalo roam!”

As noted, the comma rules followed by “oh” in written dialogue are identical to those normally followed by the word.

If we were to strip the dialogue words “she said” and “sang the camper” from these sentences, the first one would look like this:

“Oh, is that right?”

Just remember to put those commas inside quotation marks.


“Oh” as part of a longer interjection

There are a lot more interjections than just “oh” in the English language.

Sometimes, you will even find yourself faced by another interjection that includes the word “oh” within it.

In this case, it’s important to remember that the interjection needs to be treated as a complete phrase for purposes of being set off from the rest of a sentence.

In other words, if you have “oh no” at the start of a sentence, your comma needs to go after “no,” rather than after the “oh.”

That said, in some contexts (mostly on the Internet), you will see people place commas or even periods in between the words that make up an interjection.

This is done mostly for comedic effect, or to show extreme surprise, and isn’t really appropriate in other types of writing.



“Oh my! Really?”

“Oh no you didn’t!”

“Oh. My. God!”


In our first example, “Oh my!” is a complete interjection. The speaker is not talking about something that belongs to them. Rather, they are saying “Oh my!” to express surprise.

Interjections are very colloquial, so it shouldn’t be a surprise that they are used in pretty non-standard ways.

This is why they shouldn’t be used in formal writing in most cases. The second sentence above is a great example.

Although it looks like the comma should come after “no,” and that interjection is “oh no,” in fact the entire sentence is a single interjection.

In this case, you don’t use a comma at all, just as if “oh” were on its own and followed by an exclamation mark.

The final example here is probably a text message sent by someone who is completely shocked or exasperated.

The period between each word in the sentence shows extreme surprise, which is then compounded by the exclamation mark at the end.


“Oh” as part of an adverbial phrase

Although “oh” is most often an interjection, it can also appear as part of an adverbial phrase.

An adverb is a word that modifies an adjective or adverb. They often end in -ly (quietly, quickly) although they don’t have to (never, always).

An adverbial phrase is just a collection of words that, taken together, acts like a single adverb.

There aren’t a lot of adverbial phrases with “oh” in them, but you might sometimes see the word “oh-so” or “oh so” stuck in front of an adjective or adverb.

In this case, the word “oh” is not an interjection, so you shouldn’t place a comma after it.

That’s because, unlike “oh” as an interjection, this use of “oh” is actually essential to the meaning of the sentence.



“You think you’re oh-so-clever, don’t you?”

“The food was oh so good I had to have seconds.”


In the first of these examples, hyphens are used to connect the “oh” and the “so” to “clever,” the word they modify.

This is a fairly standard way of using this adverbial phrase, and makes it clear that commas are not required.

The second example shows the nonhyphenated version. Note that a comma is not used because “oh” is not acting as an interjection in this sentence.