Just like Identifying Sentence Errors questions, Improving Sentences questions cover the same grammar over and over. In fact, there are five recurring errors on Improving Sentences questions. We call them the Big Five.

We cover all of the Big Five below in more detail. Learn to spot all five and you’ll be well on your way to beating Improving Sentences with ease.

In sentences that use the active voice, the subject does the action. For example, in the sentence My dog ate a bunch of grass, you immediately know who ate a bunch of grass: the dog. The passive voice, in contrast, identifies the performer of the action late, or even never. For example, the sentence A bunch of grass was eaten leaves the reader unsure of who or what did the eating. Writers tend to avoid using the passive voice because it creates weak, wordy sentences.

So, how do you know if you are dealing with a case of “the passives”? Usually, you’ll spot these words: is, was, were, are (or any other version of the verb to be) and the word by. If you see these words, ask yourself, What’s the action and who’s doing it? If the person (or entity) committing the action appears only at the end of the sentence, or doesn’t appear at all, you’ve got a passive voice whispering bland nothings in your ear.

Here we see passive voice rearing its horrendous head. There’s a was, a by, and the fact that you don’t know until the last word of this sentence who washed Timmy’s socks. The phrase was washed suggests that someone or something did the cleaning—a parent, a washing machine, a river in Egypt. The point is, you don’t know how the socks got washed.

In order to fix the passive voice, the performer of the action must get a place of prominence in the sentence and clear up what they’re doing. In the example above, the correct answer must make clear that Timmy’s father did the load of laundry. Both answers B and E fix the passive voice problem, but E is wordy and redundant, so B is the right answer.

A run-on sentence results when two complete sentences get jammed together. Run-ons usually sound breathless, as if an excited child is telling a story. Here’s an example of a run-on sentence:

The best way to test if a sentence is a run-on is to split the sentence in two and see if both halves of the sentence could function alone:

Because each half of this sentence is complete on its own, the two halves cannot be joined together with a comma.

Here are three ways to fix run-on sentences in Improving Sentences questions:

One of the most common remedies you’ll find on the SAT is a semicolon. A semicolon (;) signals that both sides of the sentence are grammatically separate but closely related to one another.

Another method for correcting run-on sentences is adding conjunctions. Suppose you see this run-on sentence:

If you add the conjunction and:

The run-on disappears.

Sometimes sentences contain strange relationships among clauses that can obscure the meaning of the sentence. (A clause is just a bunch of words with a subject and a predicate). Here’s an example:

This sentence suggests that despite the student council’s efforts, people didn’t go to the dance because they went to the field hockey game. You can correct this run-on sentence by adding a word that makes this relationship clear:

Okay, time for a real example:

A classic run-on. The two parts could easily stand alone:

Remember, the SAT usually fixes run-ons by exchanging the comma for a semicolon. In this case, E, which uses the semicolon method, is the correct answer.

Notice that you could have corrected the question above by turning the second half into a subordinate clause:

Alternatively, you could have inserted the word and between the two clauses:

The majority of Improving Sentence questions dealing with run-ons will require you to use one of the three methods we’ve discussed to fix the sentence.

A modifying phrase is a phrase that explains or describes a word. In standard written English, modifiers usually appear right next to the word they explain or describe. When modifiers are placed far away from the word they describe, the sentence becomes confusing because it’s often unclear which word the modifying phrase is referring to, as in the following sentence:

This sentence is problematic. We can logically infer that Jane was doing the eating, but because the modifying phrase (Eating six cheeseburgers) is so far from the word it’s intended to modify (Jane), figuring out the meaning of the sentence takes a lot of work. It could very well seem as if “nausea” rather than “Jane” is being described. Therefore, the meaning of the sentence could be that “nausea” ate six cheeseburger fries. The sentence as-is does not convey the meaning the writer intended.

When you see a modifier followed by a comma, make sure the word that the modifier describes comes right after the comma. A corrected version of this sentence could read:

The phrase eating six cheeseburgers describes what Jane is doing, so Jane’s name should come right after the phrase.

Another way to correct the sentence:

Now take a look at this sample question:

The misplaced modifier in this sentence confuses the meaning of sentence. As it is, it sounds like Marcel has a bargain price, but he certainly isn’t for sale. That means you can cut A right away, since it just preserves the underlined portion of the sentence. Cut B since it also identifies Marcel as the object with the bargain price. C uses the possessive awkwardly and uses them incorrectly to refer to the bargain price. E looks better, but the phrase the jeans were snatched up uses the passive voice.

D is the correct answer. In D, the phrase bargain price modifies designer jeans rather than Marcel. The correct answer solves another problem with the original sentence, which is the phrase having a bargain price. Having does not clearly express the relationship between the jeans and Marcel’s purchase. In the correct answer, the phrase due to suggests that Marcel bought the designer jeans because they had a bargain price.

We covered parallelism in the Identifying Sentence Errors chapter, but we give it another brief review, since it’s also likely to show up in Improving Sentences questions.

In every sentence, all of the different components must start, continue, and end in the same, or parallel, way. It’s especially common to find errors of parallelism in sentences that list actions or items. In the example below, the pool rules are not presented in the same format, which means there is a parallelism error.

The first two forbidden pool activities end in –ing (-ing words are called gerunds), and because of that, the third forbidden thing must also end in –ing. If you start with gerunds, you must continue with gerunds all the way through a list.

Here’s a sample Improving Sentences parallelism question:

The description of the shopping spree’s powers begins with an infinitive, to raid. Therefore, on the other side of that and, we should find another infinitive. Instead, the original sentence contains the phrase she could eat, which is not parallel. E, the correct answer, balances both sides of the equation by substituting to eat. In its corrected form, the sentence is made nicely parallel and balanced by the two infinitives:

Wordiness means using more words than you absolutely need. It’s the crime you commit when you’ve only gotten four pages written of a six-page paper and it’s 1 a.m. the night before the paper’s due. It’s all that meaningless redundant junk you write in a desperate attempt to fill up space. Here’s an example from a paper Justin wrote senior year:

“The history of nineteenth-century France is one marked by great periods of continuity and change.”

Here’s what Justin’s got: Wordy meaninglessness with only the vague sheen of insight. Wordiness often comes hand in hand with the passive voice, as in Justin’s weak example (“is one marked by”). Other times wordiness shows up on its own. Here’s an example:

This sentence is both wordy and passive. The underlined part could be said in half the space, and you could remove a few words without changing the meaning of the sentence at all. For example: Pierre observed the diners and motels of middle America, and these sights are depicted in his trendy paintings. But even in that succinct version, the passive voice remains: The underlined phrase does not make it clear that Pierre depicted the sights. The phrase sights that are depicted makes it sound like a disembodied hand put paint on canvas.

If you encountered this question on the test, you could immediately eliminate A if you realized there was a problem to begin with. Both B and C repeat the original mistakes. They are wordy and they avoid identifying Pierre as the performer of the action. Answer choice D looks much better; it’s short and there are no red-flag phrases or words, such as having been or is, that suggest the passive voice. Suppose you suspect that D is the right answer; if you plug it back into the sentence, as you should always do, you get, Pierre observed the diners and motels of middle America, and his depiction of these sights in his trendy paintings. This newly created sentence is actually a fragment, and therefore grammatically unacceptable.

So you come to E: brief, clear, to the point, and entirely devoid of the passive voice. Does it check out? Pierre observed the diners and motels of middle America, and he depicted these sights in his trendy paintings. Yes. E avoids wordiness, names Pierre as the performer of the action, and is a grammatically correct sentence.

In addition to the Big Five, you’ll likely see a question once in a while that deals with one of these four concepts:

Conjunctions are connecting words such as and, but, that, and or. They help link two parts of a sentence together. Suppose you have two sentences:

A conjunction such as and enables you to connect the two halves of the sentence:

Improving Sentences questions test you on conjunctions by including sentences in which the conjunction makes the sentence illogical or clunky.

The right answer is D. In this sentence, the conjunction that expresses the function of the novel more smoothly than the clunky phrase and it does.

Fragments are almost the opposite of run-on sentences. Run-on sentences have clauses squashed together and joined incorrectly. Fragments have no independent clause and therefore are incomplete sentences.

In this sentence, the clause lacks a proper verb for the subject (the hunchback vice principal). The sentence would be complete if it read, The hunchback vice principal growling at terrified students was notorious for his brutal tactics. Notice though that the answer choices don’t fix the fragment that way. Instead, the correct answer, E, takes away the problem of expectation altogether. When you read The hunchback vice principal growls at terrified students, you don’t expect the sentence to continue. He growls and that’s the end of the story.

Bad coordination happens in gym class when you trip over your own feet or crash into someone else on the field. Bad coordination in a sentence happens when two clauses are joined together with a word that makes their relationship confusing.

The sentence makes it clear that John creates his own T-shirts. He also designs logos for the T-shirts. So should the word but express the relationship between these two activities? No, because the two activities are closely related. The word but would make sense only if the sentence said something like John made T-shirts, but other than that he sat around playing video games all day. The word but suggests a contrast, a change in the direction of the sentence. If you get to the middle of a sentence and it takes an unexpected turn, look for a coordination error.

In this question, you can eliminate B because the word however is also a bad choice when joining these two clauses. It expresses the same kind of contrasting relationship as does the word but. You can eliminate E for the same reason. Answer D isn’t quite as bad as B and E, but John made T-shirts for the swim team, since he designed the logos himself doesn’t make that much sense. John doesn’t make T-shirts because he designs the logos, he makes T-shirts and designs the logos, which is exactly what C says. Bingo.

We thought it would be helpful to put together a list of conjunctions and split them up based on whether they suggest contrast or no contrast. Contrast conjunction words like but require the meaning of the sentence to change direction. For example, “I would go to school, but I don’t feel well.” Noncontrast conjunction words like and keep the sentence flowing in the same direction. For example, “After school I will practice piano and eat a snack.”

Here’s a chart to help you learn the most important contrast and noncontrast conjunction words.

Subordination problems happen when there are two subordinate clauses and no main clause. You don’t need to know what that jargon means. Instead, you just need to know subordination problems tend to occur when sentences contain more than one of the conjunction words listed above. If you see one clause that starts with although, because, if, since, or so that, and then another clause that starts with one of these words, you’ll hear the subordination problem loud and clear:

You don’t need to know that this sentence is an example of bad subordination. Just notice that the two parts of the sentence don’t go together. Why don’t they fit together? Because there’s something strange about the middle of the sentence. You hit the comma, and then the sentence takes an unexpected turn.

The first part of the sentence sets you up: Since Teddy thought his first date with Maria went well, you expect something along the lines of he invited her out again or he kissed her on her front porch, right? Instead, you get the phrase so that. That just sounds incorrect and doesn’t make a lot of sense.

Knowing the sentence contains an error allows you to eliminate A. In B, the word although gives you exactly the same sort of problem that plagues the original sentence. Same with C, because. He thought the date went well because he called her every day the next week? No. That doesn’t make sense. In E, the word and doesn’t go with the although that starts the sentence. Plug D back into the sentence to make sure it fits: Because Teddy thought his first date with Maria went well, he called her every day for the next week. Lookin’ good.

As we emphasized a few times already, relying on your ear and on what “sounds right” is dangerous on the SAT. The SAT wants you to trust your ear and go with what you think might sound right in conversation or casual English. Remember that the SAT is anything but casual and that Improving Sentences questions test standard written English, not the same English you speak with friends or family. That makes learning the rules and familiarizing yourself with these words all the more important.

Pronouns are words that take the place of nouns (words for people, places, and things)—words like she, her, hers, he, him, his, they, their, it, its, that, and which. There are a number of ways that pronouns can be used incorrectly (and we cover those in our Identifying Sentence Errors chapter), but in Sentence Improvement questions one type of pronoun error generally appears: ambiguous pronouns.

An ambiguous pronoun occurs when it isn’t clear to which noun the pronoun is referring. Take a look at the following sentence:

Wait a minute. Who bought the pants? Arnold or Ebenezer? You can’t know, because that pronoun he is ambiguous. Now most Sentence Improvement questions dealing with ambiguous pronouns won’t be quite as obvious as that last example. Check this out:

This sentence tries to hide the ambiguous pronoun she by separating it from the nouns Clay, Nina, and Melissa at the beginning of the sentence. You have to be able to see through such trickery, and notice that because there were two girls crossing the street, it’s unclear which of them saw the sign.