5 Common Grammar Errors on the SAT Writing & Language

Studying for the SAT Writing & Language might sound like an endless slog through obscure grammar rules. The secret, though, is that the test tends to reuse the same few concepts. If you take the time to master the most frequently tested grammar rules, you’ll find the SAT Writing & Language test much easier. (Here’s another SAT hack: to double-check your practice writing prompts, run them through BibMe’s online grammar checker!)

To make your life easier, here’s a list of 5 common grammatical errors tested on the SAT, with examples. 

1. Subject-Verb Disagreement

Here’s an example of subject-verb disagreement: Jessica are going to the park. Yuck! Sirens are probably going off in your head, indicating that there is indeed a grammatical error in that sentence. What you’re noticing is incorrect subject-verb agreement. In that example sentence, you know that “Jessica” is a singular subject, and therefore should be paired with “is,” not “are.”

The sentence should read: Jessica is going to the park. On the SAT, subject-verb disagreement is more challenging to spot. The test will spatially separate the verb from the subject so you don’t notice the disagreement. For example, the SAT loves to insert a prepositional phrase between the subject and the verb. Check out this sentence:

The group of high school students is going on a field trip tomorrow.

In this example, “group” is the singular subject of this sentence while “is” is the singular verb. The prepositional phrase “of high school students” is inserted between the subject and the verb to make it harder to see that “group” should be paired with “is.” Here the SAT is trying to trick you into finding an “error” in this perfectly correct sentence!

Keep an eye out for these prepositional phrases, and your score will certainly be in agreement with your grammar abilities.

2. Comma Splice

A comma splice occurs when two independent clauses (or clauses that can stand alone as sentences) are incorrectly connected by just a comma. Take a look at this incorrect example:

I went to the grocery store to buy some apples, I ended up buying a lot of snacks.

This type of punctuation error is one of the most popular errors on the SAT. To fix a comma splice error, you can:

  • Connect the two independent clauses with a semicolon

    I went to the grocery store to buy some apples; I ended up buying a lot of snacks.

  • Add a conjunction (like “and” or “but”) after the comma

    I went to the grocery store to buy some apples, and I ended up buying a lot of snacks.

  • Separate the two independent clauses into two sentences

    I went to the grocery store to buy some apples. I ended up buying a lot of snacks.

Whenever you see a comma on the SAT, make sure it’s not being used to incorrectly connect two complete sentences!

3. Wrong Comparison


Check out this grammatically incorrect sentence: The performance of my sister’s band was better than my cousin’s band.

It can be tricky to spot, but that sentence is grammatically incorrect. Right now, it’s comparing a performance to a band. For wrong comparison questions, you want to ensure that you’re comparing like with like.

To fix this error, you want to be extra clear as to what’s being compared. Here are some ways you can fix that sentence:

  • The performance of my sister’s band was better than the performance of my cousin’s band.
  • The performance of my sister’s band was better than that of my cousin’s band.

It may seem repetitive, but whenever you have a comparison, ensure you’re comparing apples with apples!

4. “Who” versus “Whom”

It’s easy to get stressed about when to use “whom” since we don’t tend to use it on a daily basis. Though it’s not one of the most common types of grammar errors, knowing when to use “who” versus “whom” will make you feel more confident when taking the SAT.

On the test, “whom” usually appears after a preposition. Here’s an example of the incorrect use of “whom”:

Whom took my scarf?

In this example, you should say, “Who took my scarf?”

So when should you use “whom?” You should use it when it’s the object of a sentence. Still not sure what that means? No problem! In most cases on the SAT, there’s a preposition in front of “whom.” So if you see “to who” in a sentence, you’ll likely need to change it to “to whom” (think of the correct phrase: “To Whom It May Concern”).

5. Incorrect Modifier


Take a look at this incorrect example: After taking a long hike through Yosemite, Ryan’s sneakers were falling apart.

Here it seems like Ryan’s shoes went hiking, not Ryan. This is a great example of an incorrect modifier. The SAT loves to begin a sentence with a descriptive phrase but not immediately identify what is described. Ensure that whatever word follows the comma after the descriptive clause is what’s being described.

To fix that incorrect example, we should say:

After taking a long hike through Yosemite, Ryan noticed that his sneakers were falling apart.

Once you’ve gotten your head around these common grammatical errors, and sharpened your eagle eye with plenty of practice questions, you’ll be ready to rock the SAT Writing & Language!

While you’re at it, check out our helpful citation guides. You may not need to demonstrate how to cite a book, create MLA citations or an APA reference page for the SAT, but these guides will help you in many other language and learning situations!