SAT Writing & Language: Grammar

Colons, Dashes & Apostrophes

Even though comma usage is the most prominent punctuation rule tested on the SAT, other punctuations such as semicolons, colons, dashes, and apostrophes are frequently tested as well.


Semicolons have two primary uses in standard modern English. The first, and most common, is to join independent clauses. Both the clause before and after a semicolon must be independent, otherwise the sentence is ungrammatical.  

A simple trick is to replace the semicolon with a period and check if the sentence is still grammatically correct. If it is, the semicolon is being used correctly.

Wrong: My favourite breakfast sandwich, beans on toast; I often make one and eat it before work.

Correct: My favourite breakfast sandwich is beans on toast; I often make one and eat it before work.

Semicolons should not be followed by any sort of conjunction, or the sentence will become ungrammatical.

Wrong: Grilled cheese is one of the best, in my opinion; and beans on toast is pretty good as well.

The second, and rarer, role semicolons play in standard modern English involves a scenario in which items in a list of three or more are themselves phrases that involve commas. One common example of this is when listing cities followed by the states or countries in which they are located.

Wrong: I visited Seattle, Washington, Los Angeles, California, and San Antonio, Texas on my vacation.

See how confusing it is to read that? It’s very difficult to keep track of which place names refer to cities and which refer to states. Imagine how difficult it would be to read if the cities named were smaller and less known? Use semicolons in the place of commas in this specific scenario to avoid confusion.

Correct: I visited Seattle, Washington; Los Angeles, California; and San Antonio, Texas on my vacation.

Note that if one item in a list includes a comma, it is appropriate to use semicolons for the entire list. For example:

Correct: I packed my sleeping bag; a pop-up tent, which I had borrowed from a friend and only used a few times; a cast-iron skillet; and some popcorn to bring on the camping trip.

Only “pop-up tent” uses a comma, but it’s still appropriate to set each item in the list off with a semicolon.

Example 1
John and I have been trying to get together for weeks now. Sometimes it is just hard to coordinate plans, people have responsibilities, after all. Maybe one day soon we’ll be able see each other again.
Sometimes it is just hard to coordinate plans; people have responsibilities after all.
Sometimes it is just hard to coordinate plans people have responsibilities after all.
Sometimes it is just hard, to coordinate plans, people have responsibilities after all.

Solution: Here, we have two independent clauses. Therefore, we connect them with a semicolon.  Therefore, we connect them with a semicolon. The correct answer is B.


A colon (:) provides further explanation for what comes before it or to introduce a list. The most important rule of colons to remember they must be preceded by an independent clause. What comes after the colon does not have to be able to stand alone. Therefore, all of the following examples are incorrect:

Wrong: A classic eggs benedict breakfast should include the following: poached eggs, English muffins, and English tea.

Wrong: The dangerous animals you have to watch out for me are: lions, tigers, and pythons.

In each of the above examples, the phrases preceding the colon are not independent clauses.

The following are the two usages of colons:

1. To list things. This is pretty self explanatory.

Example: I went to the bakery and bought three things: donuts, pretzels, and a cake.

2. To introduce information in a way that emphasizes it. The first part of the sentence still needs to form an independent clause for this to be grammatically correct, and the latter part of the sentence can be either a phrase or an independent clause; its relationship to the first part of the sentence is what’s key.

The content of the two parts of a sentence in which a colon is used for emphasis should be very closely related.

Example: There was only one thing to do: fight the pirates head-on.

The second part of the sentence answers the question, “What was the only thing to be done?”

Examples 2-3
I was wondering why he urged the group to go to the new restaurant when it dawned on [2] me: the restaurant had a special on macaroni and cheese, his favorite meal. It was adding a few extra ingredients, [3] too, bacon, breadcrumbs, and chopped-up onion rings. Of course he would want us to go there for dinner!

me; the restaurant had a special on macaroni and cheese; his favorite meal.
me that the restaurant had a special on macaroni and cheese; his favorite meal.
me, the restaurant

too: bacon, breadcrumbs, and chopped-up onion rings.
too; bacon, breadcrumbs, and chopped-up onion rings.
too. Bacon, breadcrumbs, and chopped-up onion rings.


2. The clause that follows the colon is answering the question, “What dawned on the speaker?” Answer choice B uses a semicolon to connect the clauses, which might be permissible, but B cannot be correct because it also replaces the comma that appears later in the sentence with a semicolon. Answer choice C also replaces the comma with a semicolon and thus cannot be correct either. By replacing the colon with a comma, option D creates a comma splice, so it is not correct. A is the correct answer.

3. The phrase “bacon, breadcrumbs, and chopped-up onion rings” is a specific list detailing the “extra ingredients” this particular restaurant is adding to its macaroni and cheese. A colon should be inserted before this list, after “too.” The correct answer, B, is the only answer choice that accomplishes that.
Examples 4
Today’s researchers have found that the veritable army of trained volunteers travelling the country conducting face-to-face interviews can sometimes be replaced by another army the vast array of individual volunteering details about their lives - and, inadvertently, their language - through social media.
replaced - by another army,
replaced by another army;
replaced by another army:

: The portion of the sentence after “army” describes the other type of army. We need punctuation to separate the independent clause before the word “army.” A colon does the job here. The correct answer is D.


A dash adds an additional thought to an independent clause. A set of two dashes is used in much the same way as you use a set of commas - to include non essential information.

2 Dashes = 2 Commas

When used to set off a non-essential clause, two dashes are exactly equivalent to two commas. If one dash appears, so must the other. Another punctuation mark such as a comma cannot be used in place of it.

Wrong: London - which is a very old city, has many new buildings.

Correct: London - which is a very old city - has many new buildings.

As a rule of thumb, remember that if you can take a phrase or clause out of a sentence without making the sentence grammatically incorrect, that phrase or clause should be separated from the main clause of the sentence with commas, parentheses, or dashes.

Example 5
My brother is a decent tennis player, he serves well: but his forehand could be hit with a bit more accuracy.
player - he serves well -
player, he serves well -
player and he serves well

You have first to figure out the non - essential information. In this sentence, the non-essential information is “he serves well”. That phrase should be off-set by two commas or two dashes. Based on our choices, the answer is B
Example 6
When we think about animals depicted in well-known works of art, the image of dogs playing poker - popularized by American artist C.M. Coolidge, may be the first and only one that comes to mind.
Coolidge -–

The phrase from “popularized” to “Coolidge” is a non-essential phrase. You can get rid of the phrase without altering the meaning of the sentence. There is a dash already before the word popularized, and therefore the non-essential phrase should end with a dash as well. The correct answer is B.

The choice to use two dashes rather than two commas is purely a stylistic one, and the SAT will never require you to choose between the two. The only rule is that dashes must go with dashes and commas with commas. One of the SAT’s favourite errors is to mix and match commas and dashes.

IMPORTANT: Dashes can also be used to signal a list, restatement, or additional details. Therefore, one dash often acts as a colon.


  • The preacher gave an entire sermon against eating beans - I think he’s gone mad.
  • The company leadership is faltering - the CEO embarrassed himself on the news last night - and the investors are restless.
  • I like to walk everyday - not for exercise, but for alone time.
Example 7
Wrangell-St. Elias National Park, the largest national park in the United States, represents everything compelling about Alaska. It is immense larger in fact, that Belgium.
- larger,

Solution: The independent clause in this sentence is “It is immense”. “Larger that Belgium” is additional information describing immense. Therefore, it has to be preceded by either a colon or a dash. The phrase “in fact” is non-essential and has to be set off by two commas. The correct answer is D.

The functionality of a dash and colon are often similar and confusing to students. Don’t worry, the SAT will never test you on whether a dash should be used instead of a colon, since the two are somewhat interchangeable.


The basic rules for forming possessives are quite simple:

1. Singular nouns - simply add an apostrophe followed by an “s” to indicate possession. This applies even to singular nouns that end with “s.”

Example: I really like Mike’s car.
Example: Mitosis’s properties are fascinating.

2. Plural nouns not ending in “s” - again simply add an “s” and an apostrophe.

Example: I’m always amazed by children’s capacity for wonder.

3. Plural nouns ending in an “s” - add an apostrophe without an “s.”

Example: The class’ size is getting unmanageable.

4. Compound nouns - the apostrophe should be placed at the end of the entire compound noun, not at the end of the single-word noun.

Example: My father-in-law’s taste in wine is very refined.

5. Two or more Singular subjects. Put the apostrophe after the last noun.

Example: Orange juice and grapefruit juice’s best property is their vitamin content. 

6. Two or more Plural subjects. Make each plural noun possessive independently.

Example: The companies’ and lobbyists’ argument was that corporations should be treated as people.

7. One plural and one singular subject. Make them possessive independently.

Example: My cat’s and dogs’ shots are all taken care of.

With apostrophes, it’s not so much about knowing the rules as it is about determining whether you need an apostrophe at all and, if so, whether the noun is meant to be plural or singular.

Happily, there’s an easy trick to determine whether a noun should be possessive. “Gary’s ball” is just another way of saying “the ball of Gary.” So, if you want to figure out whether a noun is meant to be possessive, try swapping the order of the nouns and, putting an ‘of’ in the middle.

Example: When my computer crashed, I lost a months work on my plan to take over the world.

Should month be possessive? Try switching it around: When my computer crashed, I lost the work of a month on my plan to take over the world.

That makes sense: the point is that all the work done in a month was lost.

Correct version: When my computer crashed, I lost a month’s work on my plan to take over the world.

Example 8
I have started two companies, which I run simultaneously. Both mine companies’s profits have soared over the last six years. I think it’s safe to say that I am a valuable employee.
Both my companies’ profits have soared over the last six years.
Both my companies’s profits have soared over the last six years.
Both my company’s profits have soared over the last six years.

The underlined sentence features two errors of possession. The first is the incorrect use of the possessive adjective “mine” instead of the possessive pronoun “my.” The second error incorrectly places an “s” after the apostrophe of “companies.” Since “companies” is a plural noun ending in an “s” only the apostrophe is only required to demonstrate the “companies” possession of something, in this case, “profits.” The correct answer is B.
Example 9
Because their families are wealthy, each of my friends’ houses has a swimming pool
friend’s house
friend’s houses
friends houses

The friends are intended to be plural because of the word “their” at the beginning of the sentence. Therefore, the correct answer is A.
Example 10
If it is improperly introduced into the environment, acid-whey runoff can pollute waterways, depleting the oxygen content of streams and rivers as it decomposes.
could pollute waterway’s,
could have polluted waterways,
has polluted waterway’s

“Waterways” should be a plural noun without an apostrophe because the sentence is stating that acid-whey runoff can pollute waterways. There is nothing indicating possession. Therefore, we can eliminate B and D. Now, the question becomes a verb tense question. Because the sentence begins in the present tense with “is,” the correct answer should also have a verb in the present tense. The correct answer is A.

Contraction Questions

A contraction is when an apostrophe is used to join two words together. Let’s look at some examples:

  • they are → “they’re”
  • would have → “would’ve”
  • could not → “couldn’t”

When you use a contraction, it’s very important that you know what words you are joining together! You should never use a contraction just because you think it might work – it’s important to be familiar with common contractions that show up on the SAT.

1. Its vs It’s

  • “It” - is a pronoun that refers to an object.
  • “Its” - indicates possession.
  • “It’s”  - refers to “it is.”

By the way, “its’” is NEVER correct. If any answer choice contains this word, the SAT is trying to trick you – don’t fall for it!

2. Whose vs Who’s

  • “Who” - a pronoun that refers to a person or people.
  • “Whose” - indicates possession.
  • “Who’s” - refers to “who is.”

3. Their vs They’re vs There

This is a little trickier because now there are three words!

  • “Their” -  indicates possession by the pronoun “they.”
  • “They’re” - contraction meaning “they are.”
  • “There” -  refers to a position or place.

4. Your vs You’re

  • “You” - pronoun referring to the person addressed.
  • “Your” - indicates possession.
  • “You’re” - contraction meaning “you are.”

NOTE: There are no cases where we should use apostrophes with the possessives “hers” and “his,” even as contractions. By memorizing these common contractions, you’ll be prepared to recognize them and know how to use them correctly in all sorts of SAT questions!

Example 11
Scientists have long known that soot particles facilitate melting by darkening the snow and ice, limiting it’s ability to reflect the sun’s rays.

Solution: The sentence is referring to the ability of snow and ice to reflect the sun’s rays; therefore the underlined word is a possessive and no apostrophe is needed. We can get rid of A and C. Now we have to determine if the possessive pronoun should be singular or plural. What has the ability to reflect the sun’s rays? Snow and ice. That’s two things, so the pronoun that takes their place needs to be  plural. The correct answer is D.
Example 12
As interesting as Russ’s findings are, though, they’re true values lies in their reminder that the Internet is not merely a sophisticated tool for collecting data but is also a rich source of data.
their true values lies in their
there true values lies in they’re
their true values lies in there

Solution: In this question,  two words in the underlined phrase could be possessive pronouns. The first is the word “they’re,” which is a contraction for “they are.” Should that word remain the same, or be replaced with the word “there” or the possessive pronoun “their?” The sentence implies that “they’re” is referring to the value of Russ’s findings, or “their value.” Therefore, we can immediately eliminate A and C.

Next, let’s look at the underlined pronoun “their” after “in.” That word also refers to findings and should be possessive. Thus, that word should remain the same, and the correct answer is B