SAT Writing: The Top 3 Grammar Errors

SAT Prep

Your vs Youre resized 600The multiple choice portion of the Writing section contains three types of questions that test about two dozen types of common grammatical errors, such as pronoun reference, conjunction choice, and verb tense. But which errors are tested the most often? In the ten tests of The Official SAT Study Guide, there are a total of 490 multiple choice writing questions, and the three following errors comprise 22% of those questions:

1. Parallel Structure (41 questions)

The most common error, which involves Parallel Structure, occurs when two or more parts of a sentence are linked by a conjunction and the parts are dissimilar in form:


The group is asking boat owners three things:

to dispense fuel only into approved containers,        

throw away all litter generated on the boat, and     

to eliminate unnecessary idling

Only two of the verbals (to dispense and to eliminate) are in infinitive form. The third (throw) is unparallel without the preposition to and thus creates an error in answer choice (B).


2. Subject and Verb Agreement (34 errors)

The second most common error occurs when the subject of a sentence does not agree with its associated verb. The College Board uses many sentence structures to disguise these errors, so they are tested frequently. Consider an example:


This sentence would be perfect if apples and cinnamon sticks permeate throughout the mill. However, it is the scent that is permeating, and since scent is singular, the verb must be permeates. Remove the phrases and clauses and look again:

The scent of apples and cinnamon sticks permeate throughout the cider mill, causing most visitors to purchase snacks while on the tour. [Incorrect]

The sentence should appear as follows:

The scent of apples and cinnamon sticks permeates throughout the cider mill, causing most visitors to purchase snacks while on the tour. [Correct]

 The correct answer is (B).


3. Modifier Placement (33 questions)

Following closely behind Subject and Verb Agreement errors for SAT frequency are problems with the placement of modifiers in sentences:


Who is using the Fujita Scale? The way the sentence stands now, the intensity is using the scale. The proper referent, be it scientists or researchers or stormchasers, is not identified, thus creating a dangling modifier. To correct the sentence, add the noun being modified:

Using the Fujita Scale, scientists can rate a tornado’s intensity on a scale of zero to six in order to predict possible damage and warn people in its path.  [Correct]

 Only choice (E) provides people as a proper noun referent.

Want to see more? Our Blue Book Database has found the following Parallel Structure, Subject Verb Agreement, and Modifier Placement questions in the Official SAT Study Guide. And if you need more assistance understanding these errors, check out the SAT Writing Bible!




Photo: Your in our prayers, courtesty of Chris Chan. Note that the difference between "your" and "you're" is NOT tested on the current SAT, but you should be on the lookout for them on the ACT!