Grammar mastery can be the key to unlocking higher scores on the SAT and ACT. The ACT’s first section and parts of the SAT Reading & Writing section evaluate your understanding of grammar, punctuation, and effective language use. Whether you’re aiming for a perfect score or looking to make steady improvements, knowing the rules is non-negotiable. Here are the essential grammar rules you need to dominate the SAT and ACT.
1. Subject-Verb Agreement
On both tests, subject-verb agreement questions require you to ensure that singular subjects take singular verbs and plural subjects take plural verbs. Look out for intervening phrases or clauses that can distract you from identifying the true subject.
Example:
- Incorrect: The group of students are excited for the trip.
- Correct: The group of students is excited for the trip.
Even though “students” is the noun closest to the verb and is plural, it’s part of the prepositional phrase “of students.” You can cross out the prepositional phrase and see that the noun that goes with the verb is actually “group,” which is singular.
2. Parallel Structure
Parallel structure means that elements in a list or comparison should match in form.
Example:
- Incorrect: She enjoys reading, to jog, and painting.
- Correct: She enjoys reading, jogging, and painting.
3. Modifiers: Placement and Clarity
For all intents and purposes for the SAT and ACT, a modifier must be placed next to the word it describes. Misplaced or dangling modifiers create ambiguity—or ridiculous scenarios.
Example:
- Incorrect: Walking to the store, the rain soaked my clothes.
- Correct: Walking to the store, I got soaked by the rain.
In the incorrect version, the rain is the noun that is walking into the store, which makes zero sense.
4. Combining Independent Clauses
Combining independent clauses correctly is a key grammar skill tested on the SAT and ACT. Independent clauses are complete thoughts that can stand alone as sentences, and they must be joined properly when combined.
Ways to Combine Independent Clauses
- Use a comma followed by a FANBOYS conjunction (for, and, nor, but, or, yet, so).
- Use a semicolon.
- Create two separate sentences.
- Make one clause dependent by adding a subordinating word like “although,” “because,” or “when.”
Example:
- Incorrect: I wanted to study for the SAT, I decided to watch TV instead.
- Correct: I wanted to study for the SAT, but I decided to watch TV instead.
- Correct: I wanted to study for the SAT; I decided to watch TV instead.
- Correct: I wanted to study for the SAT. I decided to watch TV instead.
- Correct: Although I wanted to study for the SAT, I decided to watch TV instead.
5. Colons, Semicolons, and Dashes—oh my!
While commas and semicolons show up far more often on the SAT and ACT, you need to have a solid understanding of colons and dashes if you’re aiming for a top score.
How to Use Semicolons, Colons, and Dashes:
- Colons: Use a colon to introduce a list, explanation, or example after an independent clause.
- Example: She had three goals: to study, to practice, and to succeed.
- Semicolons: Use a semicolon to join independent clauses or to separate items in a list when those items contain commas.
- Example (independent clauses): I studied all week; I was ready for the test.
- Example (complex list): The conference included attendees from Paris, France; Rome, Italy; and Tokyo, Japan.
- Dashes: Use dashes to indicate an abrupt change in thought, emphasize additional information, or replace parentheses or commas. They can also emphasize an idea at the end of a sentence.
- Example (mid-sentence): The test—which was known for its difficulty—challenged even the best students.
- Example (end of sentence): She had one goal in mind—success.
6. Commonly Confused Words
The SAT and ACT love testing your ability to distinguish between commonly confused words, like "affect" vs. "effect" or "its" vs. "it’s."
Example:
- Incorrect: The dog wagged it’s tail.
- Correct: The dog wagged its tail.
7. Sentence Structure and Fragments
Ensure every sentence has a subject and a verb and expresses a complete thought. Watch for subordinating conjunctions or punctuation errors that create fragments.
Example:
- Incorrect: Because I studied for weeks. I felt confident.
- Correct: Because I studied for weeks, I felt confident.
8. Agreement in Comparisons
Make sure comparisons are logical and complete.
Example:
- Incorrect: My score improved more than my friend.
- Correct: My score improved more than my friend’s score.
The incorrect sentence implies that "my score" improved more than "my friend" did, which…makes less than zero sense. To clarify the intended meaning, the sentence must specify that "my score" is being compared to "my friend’s score."
Practice Makes Perfect
The best way to master grammar for the SAT and ACT is through consistent practice. Work through practice questions, review explanations for mistakes, and keep these rules in mind as you prep.
Pro Tip: Be Strategic
Not every grammar rule will appear on every test, but certain rules, like subject-verb agreement and correctly combining clauses, are almost guaranteed to show up. Focus your efforts on these high-yield areas for maximum impact.
Ready to Take the Next Step?
Mastering grammar is about more than memorizing rules—it’s about applying them confidently. Use these tips as a foundation, but don’t stop here. Dive into practice tests, work with a tutor, or seek additional resources to strengthen your skills. You can also subscribe for updates or follow us on Instagram and TikTok for more tips and strategies.
Stay tuned for our next post, where we’ll dive into a unique strategy for the ACT Reading section. Good luck!
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