SAT Writing: Commas, Dashes, and Colons

In this chapter, we'll go over all the rules you need to know for each punctuation mark and give you examples and exercises that cover the full range of ways they can be tested. Just so we're on the same page, we'll first review the semicolon (covered in the Run-ons chapter).

The Semicolon

A semicolon is used to join two independent clauses.

Examples:

  • I love the game of basketball; however, I don't play it myself.
  • The tribe was left without food for weeks; the members had no choice but to resort to cannibalism.
  • Bats are nocturnal creatures; they come out only during the night.

Anytime a semicolon isn't being used for this purpose, it's incorrect. The SAT loves to use semicolons to do dirty things they're not supposed to:

Example 1
Wrong:The platter was filled with berries, crackers; and cheese.
Correct:The platter was filled with berries, crackers, and cheese.
Example 2
Wrong:Ready for the journey of a lifetime; the boy hopped on the spaceship.
Correct:Ready for the journey of a lifetime, the boy hopped on the spaceship.

The Comma

Of all the punctuation marks, the comma has the most uses. We'll only go through the ones that are tested.

1. Use a comma after an introductory clause, phrase, or modifier.
Example 3
Wrong:Although he is lactose intolerant he likes to eat pizza for lunch.
Correct:Although he is lactose intolerant, he likes to eat pizza for lunch.
Example 4
Wrong:Trapped in a mine the victims found it hard to see and breathe.
Wrong:Trapped in a mine, the victims found it hard to see and breathe.
Example 5
Wrong:At the end of the rainbow we saw a bowl of Lucky Charms cereal.
Correct:At the end of the rainbow, we saw a bowl of Lucky Charms cereal.
Example 6
Wrong:When I turn 16 I'm going to buy a car.
Correct:When I turn 16, I'm going to buy a car.
Example 7
Wrong:Because she's been so busy I haven't seen her in a month.
Correct:Because she's been so busy, I haven't seen her in a month.
2. Use commas to separate three or more items in a series.
Example 8
Wrong:His hobbies included jumping off planes, crashing helicopters and eating jellyfish.
Correct:His hobbies included jumping off planes, crashing helicopters, and eating jellyfish.
Example 9
Wrong:After college, James had three options: get a job, apply to graduate school or become a criminal.
Correct:After college, James had three options: get a job, apply to graduate school, or become a criminal.

The comma between the last two items is sometimes called the serial or Oxford comma. Although some style guides make it optional, most require it. On the SAT, the Oxford comma is required.

3. Use commas to set off nonrestrictive/nonessential elements.

I will elaborate on the terms nonrestrictive and nonessential after a few examples, but just keep in mind they mean the same thing.

Example 10
Wrong:Great white sharks the most fearsome creatures of the sea are actually less dangerous than they appear.
Correct:Great white sharks, the most fearsome creatures of the sea, are actually less dangerous than they appear.

The phrase the most fearsome creatures of the sea is nonessential because it just adds additional description to the sentence. If we take it out, what's left is still a sentence that makes sense grammatically. This is the first part to understanding nonessential elements. The following examples illustrate the second part.

Example 11
Wrong:The guy, cleaning the room, is the janitor.
Correct:The guy cleaning the room is the janitor.

The phrase cleaning the room is an essential element because it specifies which guy. In other words, there are multiple guys in the room, and we need a restrictive phrase to limit the scope of who or what we're talking about.

The best method of determining whether something is restrictive or non-restrictive is to ask yourself this question: Does the phrase narrow down what we're talking about?

If yes, the phrase is essential and SHOULD NOT be set off by commas. If no, the phrase is not essential and SHOULD be set off by commas. Take, for instance, the following two examples:

Example 12
Wrong:Students, who work hard, will ace the SATs.
Correct:Students who work hard will ace the SATs.
Example 13
Wrong:Jonathan who works hard will ace the SATs.
Correct:Jonathan, who works hard, will ace the SATs.

In Example 12, the phrase who work hard narrows down the scope of who we're talking about. Otherwise, the sentence would be talking about ALL students. It's only the students who work hard who will ace the SATs.

In Example 13, the phrase who works hard does NOT narrow down who we're talking about. We already know it's just one person—Jonathan—and he happens to work hard.

Example 14
Wrong:Stephen King's first novel Carrie was a surprise success.
Correct:Stephen King's first novel, Carrie, was a surprise success.
Example 15
Wrong:The poem, The Road Not Taken, is one of Robert Frost's most famous works.
Correct:The poem The Road Not Taken is one of Robert Frost's most famous works.

In Example 15, the title of the poem is an essential element because it narrows down which poem is being referred to. If you took out the title, the sentence would lose its meaning. In Example 14, Carrie is nonessential because Stephen King's first novel already designates which book it is and doesn't narrow anything down further. In other words, Stephen King's first novel was already enough to get us down to one book. Yes, Carrie is an important piece of information, but that's not relevant when deciding what is essential vs. nonessential.

The SAT loves to test this concept with people's occupations:

Example 16
Wrong:Crowds stood in line to see author, J.K. Rowling, at the bookstore in London.
Correct:Crowds stood in line to see author J.K. Rowling at the bookstore in London.

J.K. Rowling narrows down what author we're talking about.

Example 17
Wrong:The man at the front of the line scientist, John Willard, wouldn't stop complaining about the rain.
Correct:The man at the front of the line, scientist John Willard, wouldn't stop complaining about the rain.

John Willard is essential to scientist, so there shouldn't be a comma between them. However, the phrase scientist John Williard is nonessential to man at the front of the line because it doesn't narrow down who we're talking about any further. Therefore, the phrase as a whole should be set off by commas.

If that was a lot to take in, take a deep breath and review this section until you truly understand essential vs. nonessential elements. Because if you do, you'll fly through questions that most other students get stuck on.


Moving on, when the word that is used, it's always for restrictive/essential elements (commas are unnecessary) whereas which is usually used for nonrestrictive/nonessential elements (commas are necessary).

Example 18
Wrong:Runners around the world participate in the Boston Marathon which is 26 miles long.
Correct:Runners around the world participate in the Boston Marathon, which is 26 miles long.
Example 19
Wrong:The path, that we took yesterday, is 15 miles long.
Correct:The path that we took yesterday is 15 miles long.
Example 20
Wrong:Next to the Japanese restaurant, I like, is the ice cream place.
Correct:Next to the Japanese restaurant I like is the ice cream place.

The essential phrase I like is just the shortened version of that I like. The word that is sometimes omitted.

Example 21
Wrong:Lions are carnivorous or meat-eating mammals.
Correct:Lions are carnivorous, or meat-eating, mammals.

Phrases that help define a previous term in this manner are nonessential.

4. Use commas to set off transitions and intervening phrases.

This rule piggybacks off the previous one since most transitions and intervening phrases are nonessential to the sentences they're in, but more examples never hurt anyone.

Example 22
Wrong:Some animals are nocturnal; for example the coyote hunts during the night.
Correct:Some animals are nocturnal; for example, the coyote hunts during the night.
Example 23
Wrong:When I told my parents I was pregnant, they were to my relief supportive and understanding.
Correct:When I told my parents I was pregnant, they were, to my relief, supportive and understanding.
Example 24
Wrong:Penguins unlike most other birds cannot fly.
Correct:Penguins, unlike most other birds, cannot fly.
Example 25
Wrong:Most bats are blind. Their sense of hearing however is amazing.
Correct:Most bats are blind. Their sense of hearing, however, is amazing.

The Dash

The dash (—) serves two purposes:

1. To set off and emphasize interrupting phrases or in-between thoughts, often for dramatic effect

Examples:

  • All our kitchen equipment—from the steel pans used for sauces to the premium-grade oven—had to be sold to cover our losses.
  • The Loch Ness Monster—a sea creature that is rumored to exist but has never been found—supposedly comes out only during the winter.
  • When my teacher found the cookies I was hiding—all 154 of them—she ate them all herself.
  • My cousin was a world-class wrestler—he still is—but now he focuses on coaching others.
Dash Rule 1
When dashes are used this way, they must be paired up, much like commas when setting off nonessential phrases. In fact, dashes can take the place of those commas when a dramatic effect is appropriate.
Dash Rule 2

Once dashes are paired up, the sentence must still make sense on its own if the interrupting phrase between the dashes is taken out. Take a look at this example:

The homerun ball smashed through—the neighbor's window—and rolled into the living room.

This sentence is incorrect because it doesn't make sense if the neighbor's window is taken out. Smashed through what? The correct version would not use dashes at all:

The homerun ball smashed through the neighbor's window and rolled into the living room.

If you just keep this first purpose of dashes in mind, you'll be fine on the SAT, because the second purpose is just a more specific version of the first one.

2. To signal a list, restatement, or additional detail

Examples:

  • The city is full of people you would never meet in my hometown—bums, actors, models, the crazy, the oddly dressed.
  • Consider the amount of paper that's wasted by unnecessary printing—a hundred thousand pages, three times as much as what our competitors use.
  • I like to walk everyday—not for exercise, but for alone time.
  • Everywhere we traveled in Kyoto there were vending machines—some served green tea while others carried only juice.
  • Frank took the goldfish from the bowl, carried it to the bathroom, put it in the toilet—and dropped it.

The Colon

First, some examples:

  • A classic eggs benedict breakfast should include the following ingredients: poached eggs, english muffins, bacon, and hollandaise sauce.
  • Tokyo is one of the cleanest cities in Asia: the street cleaners sometimes have no work to do.
  • Cambridge is home to two of the best universities in the world: MIT and Harvard.
  • I had no choice but to utter the truth in front of the judge: my brother was guilty.

Colons are used after an independent clause to direct attention to a list, a noun phrase, or another independent clause that summarizes or clarifies the first. But wait a second! A dash can do the same thing! Yes, a dash can do the same thing, but don't worry. You'll never be tested on ambiguous cases where a colon is interchangeable with a dash. You do, however, need to know two rules:

Colon Rule 1

A colon can only come after an independent clause. Therefore, all of the following are incorrect, even though they may seem like correct uses of the colon:

  • The dangerous animals you have to watch out for are: lions, tigers, and pythons.
  • The evidence consists of: emails, text messages, and phone calls.
  • The local bakery sells many delicious desserts such as: cheesecake, lemon tarts, and brownies.
None of the examples above need the colon.
Colon Rule 2
While a dash can often times replace a colon, a colon cannot always take the place of a dash. When dashes need to be paired up, for example, colons cannot be used instead:
Wrong: My cousin was a world-class singer—he still is: but now he focuses on teaching others.
Correct: My cousin was a world-class singer—he still is—but now he focuses on teaching others.

Common Punctuation Misuses

Before we get to some exercises, it'll be helpful to review some frequently tested punctuation misuses.

1. Don't use punctuation before prepositional phrases (typically at, for, in, of, on, to, with).

There are definitely exceptions, so don't be too automatic with this rule, but on the SAT, punctuation before a preposition is almost always wrong. This rule especially holds when the preposition is one that usually goes with its preceding words (e.g. the of in consists of). Some examples will clarify:

Example 26
Wrong:She was waiting, at the train station.
Correct:She was waiting at the train station.
Example 27
Wrong:The police investigation, of the crime scene, didn't turn up any clues.
Correct:The police investigation of the crime scene didn't turn up any clues.
Example 28
Wrong:Robert wants to make changes; to the essay before we submit it.
Correct:Robert wants to make changes to the essay before we submit it.
Example 29
Wrong:Rolex watches are designed: with elegance, style, and luxury in mind.
Correct:Rolex watches are designed with elegance, style, and luxury in mind.
Example 30
Wrong:Andy Murray, of Great Britain, competed intensely, for the gold medal in tennis.
Correct:Andy Murray of Great Britain competed intensely for the gold medal in tennis.
Example 31
Wrong:The runner was surprised—by the number of people who showed up to cheer him on.
Correct:The runner was surprised by the number of people who showed up to cheer him on.
2. Don't use any punctuation after such as, like, or including
Example 32
Wrong:The Thai restaurant serves noodle dishes such as: pad thai, pad see ew, and kua gai.
Correct:The Thai restaurant serves noodle dishes such as pad thai, pad see ew, and kua gai.
Example 33
Wrong:When I tried frog legs for the first time, I thought it tasted like: chicken.
Correct:When I tried frog legs for the first time, I thought it tasted like chicken.
3. Don't use any punctuation before that
Example 34
Wrong:The report indicates, that the pollution above Beijing has reached an all-time high.
Correct:The report indicates that the pollution above Beijing has reached an all-time high.

There are exceptions, but this rule will serve you well much more often than not, especially on the SAT.

4. Don't put semicolons, dashes, or colons where commas should be used
Example 35
Wrong:The officer took aim at the target, a life-like image of Kim Kardashian—before he pulled the trigger.
Correct:The officer took aim at the target, a life-like image of Kim Kardashian, before he pulled the trigger.
Example 36
Wrong:The patient lifted up his sleeve; revealing a deep scar on his forearm.
Correct:The patient lifted up his sleeve, revealing a deep scar on his forearm.
  1. The Rolex Daytona, the most luxurious watch ever released, sells for a staggering half a million dollars.

    A) NO CHANGE
    B) released
    C) released:
    D) released—

  2. My brother is a decent tennis player, he serves well: but his forehand could be hit with a bit more accuracy.

    A) NO CHANGE
    B) player—he serves well—
    C) player, he serves well—
    D) player, he serves well;

  3. I practice scales on the piano everyday—not because I want to, but because I have to.

    A) NO CHANGE
    B) everyday; not because I want to
    C) everyday not because I want to;
    D) everyday, not because I want to;

  4. The rapid pace of technological development however has enabled more people to survive on less.

    A) NO CHANGE
    B) development; however,
    C) development however,
    D) development, however,

  5. Drinking coffee, scientists have discovered may help prevent heart disease.

    A) NO CHANGE
    B) have discovered,
    C) have discovered. It
    D) have discovered; it

  6. I've decked out my laptop with a keyboard cover, pokemon stickers and a transparent case.

    A) NO CHANGE
    B) stickers—
    C) stickers;
    D) stickers,

  7. New York University professor and researcher, Joshua Grossman, claims that his research is definitive and trustworthy.

    A) NO CHANGE
    B) researcher Joshua Grossman
    C) researcher Joshua Grossman,
    D) researcher, Joshua Grossman

  8. Of all the things the President could have done to improve the economy, he chose to shift his attention to the one thing that was considered irrelevant; and it was health care.

    A) NO CHANGE
    B) irrelevant: being
    C) irrelevant:
    D) irrelevant to

  9. While most students at MIT use their intellect to better the world, for example, creating vaccines for deadly viruses, some are using their exceptional math skills to beat the card games in Vegas.

    A) NO CHANGE
    B) world; for example, creating vaccines for deadly viruses,
    C) world, for example, creating vaccines for deadly viruses
    D) world—for example, creating vaccines for deadly viruses—

  10. Known for its noodle dishes, the restaurant down the street always has customers, most of whom are Asian.

    A) NO CHANGE
    B) customers, and
    C) customers;
    D) customers; and

Want more questions? Our SAT Writing Advanced Guide and Workbook contains over 500 additional practice questions (grouped by topic) and 3 practice tests.

  1. A
  2. B
  3. A
  4. D
  5. B
  6. D
  7. B
  8. C
  9. D
  10. A