Punctuation on the ACT English – Everything but the Commas


Punctuation on the ACT English


Punctuation can be the most confusing parts of writing that baffle not just students, but professional writers as well. Do you know the difference between a semi-colon and a period? What about a dash and a colon?

The good news is that the ACT English section is a multiple-choice test, so your job is to pick out a correct answer out of available choices. The ACT tests a specific set of punctuation rules, most of which deal with commas. We’ve covered commas in a separate article and will concentrate this commentary around the other punctuation rules you need to know, namely: apostrophes, colons, semicolons, and dashes.

Let’s talk about each in more detail.


Punctuation on the ACT English

Apostrophes on ACT English can be really tricky and focus around possessives and contractions.


Punctuation on the ACT English

The basic possessives rule is simple and straightforward: if a word is singular or plural but doesn’t end in an “-s,” then you should add apostrophe s (‘s) to the end of the word.

The cat –> The cat’s

The women –> the women’s

If a word is plural and ends in an “-s,” then you place an apostrophe after the final -s (-s’).

The doctors –> The doctors’

Let’s look at how this works in a sentence.

Our neighbors car is so old that its about to fall apart.

This sentence is missing a few apostrophes. The sentence refers to an old car owned by a neighbor, so the correct punctuation is:

Our neighbor’s car is so old that it’s about to fall apart.

Note that the “neighbors” can refer to more than one person, in that case, the correct punctuation is:

Our neighbors’ car is so old that it’s about to fall apart.

In this example, to determine possession, you have to look for context clues within the paragraph. If the “neighbors” are referred to as they – use plural possession. If “neighbor” is referred to as he or she – use singular.

On the ACT English, possessive questions test your ability to determine if there is a need for an apostrophe and whether the related noun is singular or plural.

Many students make a mistake of thinking that only a noun representing a person (or another live thing) can be possessive. That is not true. Any noun can be possessive.

Possessives (cont’d)

For example:   An idea of a book à a book’s idea.

The project of the semester à The semester’s project.

Remember that words like “family” and “each” are singular, while word like “some” is plural.

Sometimes the context clues are difficult to find, so, if you are unsure, check the sentences before and after the noun in question.

Exception to the rule: An exception to the rule if you have to put an apostrophe after a famous person’s name that ends in an -s.

For example: for a novel by a famous author like Charles Dickens, you would say: Dickens’ novel, not Dickens’s novel.

ACT Example





The first thing to determine if whether there should be possession in this sentence. “his familys’ farm” can be rephrased to say “farm of his family.” This means that noun possession is necessary. A correct way to say this could be “family farm” but that is not one of the available choices.

We can eliminate choice A because the plural possessive of the word family is families’, not familys’.

Should it be family’s or families? Let’s look at context clues. The sentence is talking about Benjamin Banneker’s family, so “his” is a good clue. Each person usually has one family, so singular form is correct.

Because we determined that there should be possession and that the word “family” is used in singular form, the only correct option is B.


Punctuation on the ACT English

Rule: an apostrophe in contractions replaces the missing letter or letters.  

            Do not –>Don’t (apostrophe replaces “o”)

I have–> I’ve (apostrophe replaces “ha”)

ACT English tests a few very specific contraction rules.

Rule: Could, Would, Should is ALWAYS Have, and NEVER Of

When speaking, people commonly use expressions such as “could of,” “would of,” or “should of.” This usage is actually grammatically incorrect and the words could, would, and should must be paired with have. For example:

Incorrect:         I should of studied more for the final.

Correct                        I should have studied more for the final.

Remember, should of, could of, would of is ALWAYS wrong. If you are confused about any written contraction, try to replace it with a full form. This method will show you if the contraction is correct.


Punctuation on the ACT English

One of the most common mistakes students make on ACT English is confuse “it’s,” “its,” and “its’”. Do you know the difference?

It’s – can be expanded to read: it is or it has

Its – possessive form of it

Its’ – does not exist and shows up on ACT to trick unsuspecting students

For pronouns, an apostrophe always indicates a contraction.

Another common error students make is to confuse their vs. there vs. they’re and whose vs. who’s. For more details on those, check out our article on word choice.

Colons, Dashes, and Semicolons

Punctuation on the ACT English

So far, in this article we’ve discussed apostrophes and we have a separate article dealing exclusively with commas – that leaves only three more punctuation marks: colons, dashes, and semicolons. These punctuation marks are frequently tested in combination with commas and, like commas, they define relationships between clauses and phrases. Also, like commas, students should use caution not to make an error by adding too many punctuation marks. When in doubt, it’s better to remove a punctuation mark than to add one.

Keep in mind that colons, dashes, and semicolons are almost always tested alongside commas in sentence fragments and sentence structure questions.


Punctuation on the ACT English

Semicolons’ job is to connect two independent clauses – they are only correct if they can be replaced with a period. Let’s look at a few examples:

Incorrect:         After noticing that his new favorite show has been on for 5 seasons; Ben vowed to watch all episodes.

This sentence is incorrectly punctuated because the expression “after noticing that his favorite show has been on for 5 seasons” is not an independent clause; it is an introductory phrase that must be set off with a comma. The correct form of this sentence is:

Correct:           Ben noticed that his new favorite show has been on for 5 years; he vowed to watch all episodes.

Because semicolons are interchangeable with periods you will never be asked to choose between them. The differences are purely stylistic. You can use this information to your time-saving advantage and immediately eliminate both answer choices if the only difference between them is that one has a period and the other a semicolon.

There is another, somewhat obscure rule for semicolon use – to separate items in a list (especially if the items include commas).

My college graduation was witnessed by many people, including my friends and family; my colleagues from work; and my long-time teammates.

There is a tiny chance that the ACT might test this topic, so we are including it here. If you have extra time, you can learn this rule, but I would spend the majority of time learning the rules that are almost guaranteed to be questioned.


Punctuation on the ACT English

Colons are easy to confuse with semicolons because they look and sound similar to each other. In fact, colons can (but do not have to) connect two independent clauses, but they are usually used before a list or explanation.

The main rule for colons is that they must come after a complete clause, but don’t necessarily have to be followed by a complete clause. To test whether a colon is a proper punctuation, check if the sentence would still make sense if you put a period at the end of a clause before a colon. If it does not, if a list or explanation follows, you cannot use a colon to introduce it.

Incorrect:        Henry’s leased office came with necessary equipment including: copy machine, printer, and coffee maker.

Incorrect:         Henry’s leased office came with necessary equipment such as: copy machine, printer, and coffee maker.

Correct:           Henry’s leased office came with necessary equipment: copy machine, printer, and coffee maker.

The first two examples are incorrect because the parts that come before the colon are not complete sentences. The last version correctly uses the colon before a list of the “necessary equipment” in Henry’s office. If you have trouble understanding why the first two examples are incorrect, read our article on sentence fragments and run-ons.


Punctuation on the ACT English

The great thing about dashes is that they are a multi-use punctuation mark. The ACT English section only tests two uses of dashes – so that’s what we are going to focus on here. Dashes can be used to set off a non-essential clause (like commas) and they can precede an explanation or a definition (like colons)

As a reminder, a non-essential clause is extra information that can be removed without changing the meaning of the sentence.

When dashes are used to set-off the non-essential clauses, you should make sure not to mix them up with commas – to set off a non-essential clause, you must use either two dashes or two commas; never use a combination of one dash and one comma.

You can use this information to your time-saving advantage and immediately eliminate identical answer choices if the only difference between them is that

  • one has two dashes and the other two commas;
  • one has a dash and the other a colon;
  • there is a combination of a dash and a comma.

Dashes (cont’d)

Note: a trick ACT uses is to place a comma in the underlined phrase and a related dash in an un-underlined section. If you are not reading full sentences, you might miss that the dash/comma combination are setting off an essential clause and should be replaced with a dash/dash or comma/comma pair.

Incorrect:        Mary was reading a book when her kitten – a playful calico, jumped on her back.

Correct:           Mary was reading a book when her kitten – a playful calico – jumped on her back.

Correct:           Mary was reading a book when her kitten, a playful calico, jumped on her back.

By far, the most common way the ACT tests dashes is to off-set non-essential clauses. Occasionally, dashes can be tested as an introduction to a list or explanation.

Mary’s playful kitten startled her – he jumped on her back.

ACT Example

Let’s look at an example of when to use and not use a dash.



In this example, we are asked to join the two sentences. We need to determine what type of punctuation is appropriate here. The phrase “on the right, side, after they have moved through history” is not a complete sentence, so we can eliminate choices F and G because a period and a semicolon are stylistically identical. We are left with choices H and J, one of which has a comma and the other, a dash. Remembering that dashes or commas must come in pairs to offset a non-essential clause, we notice that there is a comma after the phrase “on the right side.” That means that there should be another comma in the underlined section. This makes H the correct answer.

Let’s look at another example:



Sometimes when trying to answer ACT questions, it’s easier to use process of elimination and explain why certain things don’t work. Looking at the sentence in question, we can eliminate choice D because the phrase “but versatile boat” is not an independent clause, and a semicolon is not an appropriate type of punctuation. We can rule out the dash in choice C because, by definition, it must come after a complete thought and the phrase “but all kayakers can appreciate the nuances of nature as they travel on water in this simple” is not a complete sentence and doesn’t make sense if we removed the latter part.

The comma that comes before a coordinating conjunction “but” in choice A is tempting but incorrect because it is used as a contrasting transition between two words that describe the same boat and you should never put a comma in the middle of a complete thought. That leaves choice B which is the correct answer.

Remember – ALWAYS consider if a punctuation mark is necessary. It often isn’t.

When in doubt, leave it out.  

Summary of Punctuation Rules on ACT English

In this article we have covered many rules and strategies for answering punctuation questions on ACT English. Here is a summary of the main points:

Punctuation – Key Points:

  • Possessives – the apostrophe comes before -s for singular nouns and plural nouns that don’t end in an -s and after the -s for plural nouns that do end in an s. For example,
    • Woman à singular (Woman’s)
    • Women à plural (Women’s)
    • Neighbors à plural (Neighbors’)
  • Contractions – the apostrophe replaces missing letters. Ex: They have à They’ve.
  • Possessive Pronouns don’t have apostrophes. Ex: Its (its’ does not exist and is a trick).
  • Semicolons connect two complete clauses. Each can stand as its own sentence.
  • Colons come after an independent clause and introduce a list or explanation.
  • Dashes set off non-essential clauses and introduce lists or explanations.

Punctuation – Helpful ACT Strategies:

  • To determine possession, use “of.” Ex: My friend’s dog à The dog of my friend.
  • Use context clues to determine if a possessive noun is plural or singular.
  • Remember that nouns are not only person, place, or thing. Words like idea, family, thought are also nouns.
  • Should, could, and would must always be paired with “have,” not “of”
  • You will never be asked to choose between interchangeable punctuation marks. If the punctuation mark is the only difference between two answer choices, you can confidently eliminate both.
  • Punctuation marks around non-essential clauses must be either a pair of commas or a pair of dashes – never a combination.
  • Use process of elimination to rule out wrong answers (rather than trying to pick out the correct one) when faced with seemingly similar punctuation marks.
  • If one choice does not have a punctuation mark – give it careful consideration. It could be the correct one.
  • Never rule out an answer just because you are not sure what it means.
  • Be sure to study rules on comma usage and run-on sentences.

Next Steps

Commas are frequently tested in conjunction with other types of punctuation. Make sure you know rules of comma usage on the ACT.

Not sure what to study, check out this article on the most frequently tested ACT grammar rules.

Need a big picture view? Learn the 5 key concepts you need to know to ace the ACT English.

If you would like to watch a video related to this blog post, please follow this link.


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