Cracking the ACT English Code: Usage and Mechanics (Part 1)

With today’s smartphone-driven jargon, it is easy to lose sight of the foundational grammar upon which the rich English language is built: a texting dialogue filled with acronyms, sentence fragments, abbreviations and emojis doesn’t exactly hold us accountable for remembering these rules. Unfortunately, the ACT still does.

With that, let’s take a look at the first of the ACT English section’s two primary categories to know & tackle: Usage & Mechanics.

In order to be successful across this area, you must have a good grasp of English grammar, punctuation, word usage, and sentence structure. Sound intense? It shouldn’t. Strip away the fancy labeling, and you probably know–or have at least seen–a lot of this stuff. Chances are that, as a high schooler, you have read and heard enough to make many distinctions between what is correct and what is improper English.

This does not mean, however, that this ACT section will be a proverbial (Quick! What does that mean?) walk in the park. These test writers know and love a good curveball, so it will benefit even the most natural Grammar Whiz to really know her stuff–and how to apply it.

How to Spot a Usage & Mechanics Question

The ACT Usage & Mechanics question should be distinguished from the test’s Rhetorical Skills questions as the section’s “non-question” questions: They typically offer grammatical alternatives to a piece of select underlined text (pulled from a longer reading passage) along with the answer choice “No Change.” These reading passages can range from being a sentence or two long to containing a few paragraphs. The Usage and Mechanics questions–comprising 40 out of the 75 ACT English questions, or 53% of the section–always take these forms:

    1) Punctuation (10 questions total): Questions in this category test your knowledge of the conventions of internal and end-of-sentence punctuation, with emphasis on the relationship of punctuation to meaning (for example, avoiding ambiguity, indicating appositives).
    2) Grammar and usage (12 questions total): Questions in this category test your understanding of agreement between subject and verb, between pronoun and antecedent, and between modifiers and the word modified; verb formation; pronoun case; formation of comparative and superlative adjectives and adverbs; and idiomatic usage.
    3) Sentence Structure (18 questions total): Questions in this category test your understanding of relationships between and among clauses, placement of modifiers, and shifts in construction.


How to Address a Usage & Mechanics Question

That’s why you’re here, right? Let’s look at these segment components section by section.


Punctuation questions will probably look something like this:

When I was a child I loved to visit my uncle’s bakery and spend hours with him in the kitchen.


    B. When I was a child – I loved
    C. When I was a child; I loved
    D. When I was a child, I loved


Commas are sneaky, and unfortunately, questions surrounding them make the biggest appearance in this section. It can be difficult to decide if a comma is necessary or not. How did you fare on this example? The correct choice was “D) When I was a child, I loved” because a comma is needed to separate the dependent clause at the beginning of the sentence from the rest of the sentence.

Let’s look at another:

The bakery kitchen filled with the intoxicating scents of melting chocolate, warm vanilla, spicy cinnamon, and bright lemon.

2. Which of the following alternatives to the underlined portion would NOT be acceptable?

    F. with the intoxicating scents: melting chocolate
    G. with the intoxicating scents of: melting chocolate
    H. with many intoxicating scents, including melted chocolate
    K. with intoxicating scents like melting chocolate


First of all, be careful of the important little word “NOT” here! This indicates that three of these answer choices would logically fit in this sentence, requiring you to do the extra work of figuring out which could not make sense.

This question responds to your understanding of colons, and is undeniably tougher than the first example. Do this test to help you figure out where to start: As a grammatical rule, the portion of the sentence before the colon must be able to stand on its own as a complete sentence, or form an independent clause. Do the answer choices containing colons- F and G- fit this rule? F seems to, but G doesn’t quite sound right: “The bakery kitchen filled with the intoxicating scents of” cannot be a sentence on its own, since it cannot end in a preposition. G looks like a good contender, but let’s look at our other options, when substituted, to make sure:

    H) “The bakery kitchen filled with many intoxicating scents, including melting chocolate”
    K) “The bakery kitchen filled with intoxicating scents like melting chocolate”

Being able to confirm that these answers “work” simply respond to your ingrained understanding of the English language, which is what a lot of this test is. Therefore, remember to 1) read the whole sentence and 2) read the sentence in your head to be able to use the logic you already have to guide you to the right answer.

Whew! We covered a lot today. Next we will look at the other two parts of the Usage & Mechanics question type, “Grammar and Usage” and “Sentence Structure.” Happy studying!


  • Susanna Langholm

    Susanna holds a BA in Education & Liberal Studies from Smith College and has spent the better part of her college and post-graduate years helping students achieve success both in and outside of the classroom. Most recently, Susanna served as the Assistant Director for a tutoring franchise catering to college-bound exam prep students, learning a thing or two about the ACT in the process. When she’s not navigating the test-taking waters for the sake of her students, Susanna can be found reading, writing on her education blog, skiing, or planning a future filled with international travel - her favorite (but most expensive) hobby.

By the way, Magoosh can help you study for both the SAT and ACT exams. Click here to learn more!


No comments yet.

Magoosh blog comment policy: To create the best experience for our readers, we will only approve comments that are relevant to the article, general enough to be helpful to other students, concise, and well-written! 😄 Due to the high volume of comments across all of our blogs, we cannot promise that all comments will receive responses from our instructors.

We highly encourage students to help each other out and respond to other students' comments if you can!

If you are a Premium Magoosh student and would like more personalized service from our instructors, you can use the Help tab on the Magoosh dashboard. Thanks!

Leave a Reply