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Punctuation: Everything You Need to Know

Updated on
April 9, 2021
Grammar
Punctuation: Everything You Need to Know

You can’t write without punctuation. Well, you can, but your writing wouldn’t make any sense to your reader. Punctuation is as important to your writing as your word choice, syntax, and structure. When any one of these elements is missing, you don’t have a coherent piece of writing—you have a word salad.  

Most kinds of salad are great, but word salad isn’t. Avoid serving up tossed-together words by becoming a punctuation pro. 

Basic and common punctuation marks

Periods

When it comes to punctuation marks, you don’t get any more basic than periods. The period, also known as the full stop, looks like this: .

It has one job: to end a declarative sentence. 

That’s all. That’s what periods do. 

Ellipses

Ellipses look like a set of three periods together: . . .

They’re used to show that information has been omitted from a quote, usually to shorten it. 

In fiction and poetry, they’re also used to build suspense, show a speaker’s voice is trailing off or faltering, or represent incomplete thoughts. This evolved into ellipses’ use in casual conversation, like text messages and social media posts, where they’re frequently used to indicate pauses . . . or voices or thoughts fading away. 

Commas

Commas are one of the most common punctuation marks. A comma looks like this: ,

They’re also among the most commonly misused punctuation marks. A comma indicates a pause in a sentence, either between phrases, clauses, or items in a list. This is what can make them tricky—the points where you’d pause in a spoken sentence aren’t always where you’d use a comma in a written sentence. 

Apostrophes

The apostrophe is a busy little punctuation mark. It looks like this: ’ 

Apostrophes’ jobs include:

  • Creating possessive nouns (Jim’s house, the Kelleys’ car)
  • Combining words into contractions (don’t, she’ll, weren’t)

And more casually, apostrophes are used to shorten words (government becomes gov’t and the 1970s becomes the ’70s) and in quotes to show the speaker has shortened a word, for example: We looked and found nothin’.

One last note on apostrophes: Most of the time, they are not used to pluralize nouns. For example:

Don’t use them when you’re referring to a decade numerically (correct: the 1990s, incorrect: the 1990’s)

Don’t use them when the last letter follows an apostrophe (correct: don’ts, incorrect: don’t’s)

Don’t use them when describing a group of people (correct: the Chens are coming to dinner, incorrect: the Chen’s are coming to dinner)

However, the only time an apostrophe is used to pluralize a noun is when the noun being pluralized is a lowercase letter. For example: Mind your p’s and q’s. 

Exclamation points

Punctuation is exciting! 

You read that sentence in an eager, high-energy voice because it ended with an exclamation point: !

Much like the period, the exclamation point has one job: to make sentences exciting!

Just be careful not to overuse them—and in some kinds of writing, it’s best to leave them out entirely. Exclamation points can be fun in casual messages and show the passion in a character’s voice when you’re writing fiction, but they’re usually not a good choice in any kind of formal, academic, or business writing. 

Question marks

The question mark is another one-job punctuation mark. They look like ? and they’re used to communicate that a sentence is a question. 

Only use a question mark when you’re asking a direct question, like:

  • What kind of phone do you have?
  • Why didn’t my package arrive?

Indirect questions are actually declarative sentences, so they end with periods. Examples of indirect questions include: 

  • I wondered why there was so much traffic.
  • She asked herself how she could have missed the signs. 

Dashes

There are two different kinds of dash you probably use fairly regularly in your writing—and one you don’t. The two common ones are:

Em dash  —  

En dash – 

We explain the situations that call for each kind of dash in our post on using colons, semicolons, and dashes in your writing. 

And the rare one is known as a double hyphen. It looks like this: and you only use it when you’re wrapping a hyphenated word onto the next line of text. 

Quotation marks

As their name implies, quotation marks denote direct quotes. But that’s not all they do. 

They look like “ ” and they can also be used to: 

  • State the title of a work (His article, “Why Chocolate is the Best Flavor,” was published in Ice Cream magazine.)
  • Signify a word within a sentence (Please refer to the champion as “winner.”)
  • Communicate that a specific word is being used in a facetious disapproving way (The day-old pizza was “not that terrible.”)

Parentheses

When you need to add information to a sentence but the information doesn’t fit in gracefully, add it with parentheses. Generally, this information is a tidbit of detail or a quick aside.

Hyphens

Hyphens might look like dashes, but they aren’t dashes. Hyphens are used to create compound words like:

  • Load-bearing
  • Well-loved
  • Great-looking

Less-commonly used punctuation marks

Interrobang

What

When your sentence calls for a question mark and an exclamation mark, the interrobang is the punctuation mark you need. It was first introduced in 1968 and today it can be found in a wide variety of fonts. 

Brackets

Brackets might look like parentheses, but they aren’t parentheses. They come in two different forms:

Square brackets: [ ]

Curly brackets, also known as braces or squiggly brackets: { }

Square brackets are used two different ways: to add content to a quote in order to make the quote clearer and to mark a subordinate clause within another subordinate clause within parentheses. If that sounds confusing, seeing them in play visually may help:

  • “I loved it [the new movie]. I couldn’t look away,” Bob said.
  • I invited my family (Mom, Dad, my sisters [but only Melanie came] and Grandma) to come meet the new puppy. 

Squiggly brackets are rarely seen outside programming, physics, and high-level mathematics. But when they are, they’re generally used to indicate a list. 

Types of punctuation

Punctuation marks are grouped according to what they do. 

Terminal points

Terminal points are punctuation marks that end sentences. These marks are: 

  • Periods
  • Question marks
  • Exclamation points
  • Interrobangs

Pausing points

Pausing points are punctuation marks that tell the reader to pause. These include:

  • Commas
  • Colons
  • Semicolons
  • Em dashes
  • Ellipses

Identifying quotation

And then there are the punctuation marks that identify quotations. This group includes quotation marks. 

Why is punctuation important?

Punctuation is important because it directs your writing’s flow. If your writing is a roadway, the punctuation marks are the traffic signs. They show the reader where to pause, where to come to a complete stop, and how to interpret the phrases they come across.

Different pieces of punctuation can radically change your writing’s message. Take a look at this example, which you might have seen before:

  • Let’s eat Grandma.
  • Let’s eat, Grandma.

See how much of a difference a comma makes? 

Common punctuation errors and questions

How many spaces go after a period?

One. 

If you started writing when typewriters were commonplace, you were probably taught to put two spaces after each period. This is because on a typewriter, each character takes up the same amount of space on the page, so two spaces made the start of a new sentence clearer. With computers, this isn’t necessary because word processing programs automatically adjust the amount of space between each letter.

When should I use a colon? What about a semicolon?

It’s not always easy to know when a colon or a semicolon is the right call. And to make things more confusing, there are situations where either can be appropriate

Generally, a colon is for situations where you’re introducing information and need to give it some context or you have two directly related clauses and you want to emphasize the second one. Here are both scenarios in action: 

  • We watched everything that airs on weeknights: Wheel of Fortune, Eyewitness News, and Jeopardy!
  • I’ll tell you why I’m not going to pass this assignment: I still haven’t started writing my essay. 

When you have two independent clauses, you can use a semicolon to bring them together as a full sentence. 

What is the Oxford comma? 

The Oxford comma, also known as the serial comma, is a comma placed in a list between the second-to-last item and the word “and.” Here is a quick example: 

  • I made grilled cheese sandwiches, steamed broccoli, and cut strawberries for lunch. 

That comma right after “broccoli” is the Oxford comma. Some style guides, notably the Chicago Manual of Style, require it. Others, notably the Associated Press Stylebook, do not. If you’re not sure whether to use the Oxford comma in your writing, check your style guide—if you have one. If not, whether to use the Oxford comma or not is completely your call.  

You’ll notice in this blog post and others that at Grammarly, we use the Oxford comma. But lots of other blogs don’t, and that doesn’t make their grammar less correct than ours. 

The Oxford comma can make your lists clearer because it eliminates any possibility of the reader’s misinterpreting the last two items as anything but items in the list. Take a look at how the Oxford comma clears up confusion in this list: 

  • I called two plumbers, Jack and Steve.
  • I called two plumbers, Jack, and Steve. 

Are Jack and Steve the plumbers, or did you call them in addition to calling two plumbers? The Oxford comma clarifies that. But when you’re working with a style guide that doesn’t use the Oxford comma, you can make lists like these clear by changing your word order: I called Steve, Jack and two plumbers. 

Whether you decide to use the Oxford comma in your writing or not, always make sure you stay consistent with your choice. Seeing an Oxford comma in one sentence, then seeing lists without it for the rest of the piece, can be jarring for readers and make you look like an inattentive proofreader. 

Should I use single or double quotes?

In American English, use double quotes except for when you’re writing a quotation within a quotation, like:

“I brought it to the dealership and the guy said, ‘It’ll be $50 just for me to take a look at it.’ Can you believe that?” Jessie asked. 

In British English, single quotes are typically used. 

Do periods go inside quotation marks? How about parentheses?

In American English, periods always go inside quotation marks. The same is true for commas. However, not all other punctuation marks go inside quotation marks. Dashes, colons, and semicolons always go outside quotation marks (unless they’re part of what’s being quoted) and exclamation and question marks sometimes go outside, sometimes go inside. With these, whether they go inside or outside the quotation marks depends on whether they’re part of the quote or part of the larger clause. Here’s a look at both situations: 

  • “How much do I owe you?” Jim asked the driver. 
  • I want a steak, not this “soy-based substitute”!

With parentheses, the same rules apply. If the period, or any other punctuation mark, is part of the sentence or clause within the parenthesis, it stays inside the parenthesis. If it’s part of the larger sentence, it goes outside the parentheses. 

How do I know I’m using punctuation correctly?

One way to quickly catch punctuation mistakes is to read your writing aloud. Does it sound right? If something sounds off, it might be your punctuation. 

Don’t just trust your ears to catch grammar mistakes. While some errors are easy to recognize when you listen to your writing, others aren’t so obvious. For these, Grammarly can help. 

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