A Complete Guide to ACT Grammar Rules

Feb 22, 2022 | Turito Team USA

act grammar rules

Although aspirants wonder how many rules of grammar they need to cover for the ACT exam, the ACT exam tests a specific set of grammar rules. Furthermore, you don’t need to be a grammar whiz to learn all of them!

Here we have discussed the Complete Guide to ACT grammar rules that you need to know to ace the exam. If you understand all of these rules and practice them consistently using ACT grammar rules pdf, you will significantly improve your score.

Unlike other resources, this article concentrates on presenting several instances that will help you visualize the application of the grammatical rule. After all, you must grasp the concepts to perform well on the test!

The Complete Guide to ACT grammar rules at a Glance

  • Avoiding Run-ons and fragments
  • Keeping Verb Tense consistent
  • Avoiding Wordy Phrases
  • Keeping a note of the punctuations
  • Checking for Dangling modifiers
  • Learning the Pronouns
  • Avoiding Comma Splices
  • Understanding Parallel Construction

What are the ACT English grammar rules I need to know?

1. ACT English Grammar Rules: Avoiding Run-ons and fragments

A complete sentence must contain a subject, and a related predicate punctuated correctly. A run-on sentence arises when two or more complete sentences are joined improperly. A run-on sentence consists of many complete thoughts that are not punctuated correctly. Keep in mind that the length of a sentence does not indicate its correct formation.

For instance: He writes the music, she plays the guitar.

‘He writes the music’ and ‘she plays the guitar’ are independent phrases with a subject and verb and communicate complete thoughts.

Strategies for Correcting Sentences:

  • Create a compound sentence.
    Inserting coordinating conjunction (for, nor, and, but, or, so) plus a comma correctly connects these independent clauses. This type of sentence is called a compound sentence.

Correct sentence: He writes the music, and she plays the guitar.

Use Periods: The easiest way to fix a run-on is to break the sentence into small sentences with a period. It also works well with longer sentences.

Corrected sentences: He writes the music. She plays the guitar.

2. ACT English Grammar Rules: Keeping Verb Tense Consistent

Another rule is learning the subject-verb agreement basics. The verb tense should be consistent across sentences, paragraphs, and the body of whatever you are writing—again unless there is a compelling reason to change it.

Let’s look at the sentence below:

When my mother goes to the supermarket, she bought a treat for everyone.

(‘Goes’ is in the present tense, whereas ‘bought’ is in the past tense—and you don’t have a compelling reason to switch.)

Correct Sentence 1:
When my mother goes to the store, she buys a treat for everyone.
(Both of these verbs are present tense.)

Correct Sentence 2:
When my mother went to the store, she bought a treat for everyone.
(Both of these verbs are past tense.)

3. ACT English Grammar Rules: Avoiding Overly Wordy Phrases

ACT firmly believes in “less is more”: use fewer words to convey the same message.

One might think it looks more professional or academic when a sentence contains multiple words. However, this is not the case. Often, a single word is preferable to a large number of words.

For example, She wore a jacket in blue color.

(Blue is, by definition, a color.)

We can write the same sentence as She wore a blue jacket.

4. ACT English Grammar Rules: Keeping a note of the Punctuations

Punctuation is one of the most common English grammar concepts that appear on the ACT. The ACT assesses students’ use of commas, colons, semicolons, dashes, periods, question marks, and exclamation points.


Some common uses of commas are:

Uses of comma Example
To separate words in a series of three or more items. We had chips, cake, coffee, and cutlets.
To separate two adjectives when they are interchangeable. He is a healthy, strong man.

Some common uses of colons are:

Use of Colon Example
They may indicate a list coming up. She would buy four things: chairs, tables, clothes, and utensils.
Use a colon to add two sentences. It happens when the second sentence summarizes and concludes the first. Life is like a riddle: most people can’t solve it.

Question mark
Question marks are generally put after direct questions.
Example: “Is this the place?”

Use an exclamation point at the end of a sentence to express strong emotions, feelings, or shock.
Example: “You did a great job!”

5. ACT English Grammar Rules: Checking for Dangling modifiers

A dangling modifier is a phrase that modifies a word that is not clearly stated in the sentence. A modifier describes or gives more detail about a concept. This mistake occurs when the desired subject of the modifier is missing from the sentence, and instead, a different subject appears in its place.

Example: Having injured her hand, it was difficult to write the exam.

Corrected Sentence: Having injured her hand, Seema had difficulty writing the exam.

The first sentence in the example above fails to specify whose hand was hurt. It fails to clarify the subject of the introduction modifier phrase. The subject, i.e., Seema, appears directly after the modifier phrase in the corrected sentence.

There are two methods of correction:
Method 1
One method of fixing is leaving the modifier as it is and rewriting the main clause, to begin with, the subject being modified, as done above.

Method 2
The other method of fixing it is to include the subject in the introductory phrase and let the main clause remain as it is.

Correct Sentence:
Because Seema had injured her hand, it was difficult to write the exam.

6. ACT English Grammar Rules: Learning the Pronouns

A pronoun is a word that replaces a noun. We use pronouns so that we don’t repeat the same noun over and over again in a sentence or paragraph. It is important to know the basic difference between the most common types outlined in the chart below.

Subject Pronoun Object Pronoun
I Me
We Us
You You
They Them
He Him
She Her
It It 

Error: Me and my parents ate lunch.
Correct: My parents and I ate lunch.

Commonly Confused: That vs. Who vs. Which
This concept is simple:

Who  That  Which
When describing people

For Example, 

This is my friend Vijay, who I met back in college.

When describing groups or objects or non-humans

Ex. Alice called the bakery that makes Richard’s favorite cake.

When describing objects,

Ex. My birthday dress, which I bought last week, fits me perfectly.

7. ACT English Grammar Rules: Avoiding Comma Splices

A comma splice occurs when a comma is used wrongly to combine two independent clauses into one sentence. If you are wondering what an independent clause is, it is a complete sentence that can stand on its own grammatically. It should have both a subject and a verb.

For example, I went to the mall.
It is not correct to join two independent clauses with a comma. This error is called a ‘comma splice.’

Ways to Fix Comma Splices

  • There are different ways to fix a comma splice. First, you can break the part before the comma and the part after the comma into two separate sentences using a period.
    I went to the mall. Alice was there.
  • Secondly, you can join two independent clauses by adding coordinating conjunction such as “and” after the comma.
    I went to the mall, and Alice was there.
  • Finally, you can change one of the independent clauses to a dependent clause by adding a subordinating conjunction. For example:
    When I went to the mall, Alice was there.
    I went to the mall because Alice was there.

If the dependent clause comes first, you must use a comma to join the two clauses. If the dependent clause is second, you don’t need to use a comma.

8. ACT English Grammar Rule: Understanding Parallel Construction

The term “parallel construction” refers to the writing of words or phrases in the same order. If one sentence in a list starts with “of,” the rest of the list should as well. Other sentences should utilize the verb form ending in “ing” if one phrase does.

Here’s an example of sentence sections that don’t match: I like ice skating, skiing, and to hike.

There are two “ing” verb forms and one infinitive in this example (“to hike”). We can boost parallelism by employing matched parts:

Correct Sentence: I enjoy ice skating, skiing, and hiking.

Now, Since you know the Complete Guide to ACT grammar rules, it’s time to practice. Grab a copy of the ACT grammar rules pdf and start practicing to ace your exam!

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