GMAT Exam: A Simple Guide To Solving Sentence Correction Questions - A Review of English Grammar and Mechanics

A Review of English Grammar and Mechanics
Reviewing grammar rules will truly improve your score on the GMAT. Not only will you be better prepared for the Sentence Correction questions, but your ability to do well in writing your Analytical Writing Assessment will improve, too.

Remember, a computer grades the AWA (along with a human reader). Computers can’t pick up a lot of nuances in writing, but they can be programmed to pick up on grammatical errors. Eliminate those, and the computer will like your essay a bit more!

Let’s take a look at some of the grammar and mechanics conventions you’ll need to know on the GMAT.

This guide can’t substitute for a thorough overview of grammar and mechanics if you are totally at sea.

We suggest reading a good book on grammar rules such as The Elements of Style for that level of help.

Verbs
A large proportion of the GMAT’s Sentence Correction questions will be about verb usage. Incorrect verb tense and lack of subject-verb agreement are distressingly common errors, and they make writing look inexpert. Luckily, while these errors are very easy to make, they’re also pretty easy to spot!

Let’s look at the most common type of error you’ll have to correct on the GMAT, subject-verb agreement.
A verb is a word that describes action (like eating, running, reading) or a state of being (am, is, was, were).

Subject-Verb Agreement
You remember from your high school English classes that the subject of a sentence is the person, place, or thing taking action, while the verb tells you what action is being taken. These, the subject and the verb, must be in agreement. Forget about trying to remember a complicated rule about words ending in -s.

Instead, focus on this: If your subject is plural, your verb must be plural.

Likewise, if your subject is singular, your verb must be singular:
I was
We were
They are
She is
The dogs ran
The dog ran
The clowns sing
The clown sings

Remember that you is an exception. It’s always plural, even when you’re talking only about one you.
So:
You lift me as a person.
You lift me as a class.
Same spelling, see?

Of course, the GMAT is rarely that easy. Take a look at this sentence:
Elsie, like many cows, eat a great deal of hay.

On first glance, you might think that there’s no problem here, probably because “cows eat a great deal of hay” sounds correct. The problem is that while the verb is eat, the subject isn’t cows. It’s Elsie! And her name is singular, so the sentence should read:
Elsie, like many cows, eats a great deal of hay.

Notice how the GMAT has deliberately tried to trick you by putting the word cows, a plural noun, into the sentence. It’s hard to catch those easy mistakes, especially when you’re in a hurry.

This use of a modifying clause or phrase (such as like many cows) is a common trick on the GMAT.

The subject of the sentence is the noun that is taking action in the sentence.

Sometimes the GMAT tricksters use either … or or neither … nor.

This is confusing because when either and neither introduce multiple nouns, it seems they would need a plural verb, such as in this example:
Either Susan or David tell the story.

This seems like it might be OK, because Susan or David is more than one noun. But either renders the noun singular, no matter how many singular nouns follow. So the correct form is:
Either Susan or David tells the story.

When either and neither are used with plural nouns or pronouns (or with both singular and plural nouns), the verb should agree with the noun closest to it, as in the following example:
Either Susan or the boys are riding the bus.

Another way the GMAT test-makers will try to trip you up in subject-verb agreement is with collective nouns—such as audience, council, group, majority, series—which are almost always treated as singular nouns on the test. (This is not always the case in real life, so be careful.)

In other words, the GMAT favors a sentence such as this:
The audience was euphoric.

over this:
The audience were euphoric.

They do the same thing with singular collective pronouns such as each, everyone, everybody, nobody. Again, there are rare exceptions when the way a sentence is phrased might make the verb plural, but on the GMAT, you can count on these words being singular:

Each member of the audience was euphoric.
Nobody wants to do that again.

No matter how the GMAT tries to trip you up, the key is to find the subject in the sentence—the person, place, or thing taking action—and determine whether it is plural or singular. Then make your verb match.

Verb Tense
Verb tense tells readers when the action in the sentence happened or will happen. The three most common forms of verb tense are past (We played.), present (We are playing.) and future (We will play.).

Of course, there are many, many more forms of verb tense, but for the purposes of the GMAT, you don’t need to be able to list, say, future perfect tense. Rather, you need to be aware of consistency in verbs throughout the sentence. If the sentence begins with action in the past, the rest of the sentence (on the GMAT, anyway) should also be in the past.

You don’t have to identify parts of speech or types of verb tense on the GMAT. You just need to be able to make words work together as smoothly as possible.

It is quite common to find that in the underlined portion of a GMAT Sentence Correction question there is more than one verb, and the tenses of the verbs do not match:
Sheila gave Rachel the key to the house after Rachel would stop by.

We can see what the sentence means, and it may be written in a way that is familiar to us in casual conversation. But the sentence is grammatically incorrect, combining past tense (gave) and conditional (would stop).

A better form of the sentence is:
Sheila gave Rachel the key to the house after Rachel stopped by.

Now the two verbs (gave and stopped) agree in their tense.

Pronouns
Since the GMAT mimics the mistakes we most frequently make in real life, it makes sense that pronoun problems would be the second-most-common form of error that needs to be corrected on the test. We make a lot of pronoun mistakes!

Pronouns are the words we use to replace nouns or proper nouns (names), including he, she, it, they, and them. There are other pronouns (technically, there is often a pronoun), but you will not see many GMAT questions concerned with them.

Pronouns replace nouns in sentences. Proper nouns are names used as nouns. They usually begin with capital letters. The word princess is a noun. Princess Elise is a proper noun. She is a pronoun.

There are two basic forms of pronoun mistakes that you’ll have to correct on the GMAT.

The first is called a pronoun reference error. This error occurs when the sentence does not make clear to the reader what or who the pronoun is referring to because the related noun (called the referent or antecedent) is unclear or missing.

Here is an example:
According to Victoria, Kate and Louis wanted to take Mark shopping for a new car, but he didn’t know which one of them to choose.

Here, we don’t know if the he refers to Mark or Louis, and whether them refers to the people in the sentence or to cars.
This error is fairly easy to spot. If you see pronouns in the underlined portion of the sentence, ask yourself if it is immediately clear which noun they are referring back to, keeping in mind that your initial impression may not be the correct response. Just be sure to look for the answer that best improves the sentence. In that example, you’ll need to find the answer that corrects for both he and them.

Another common form of pronoun error that the GMAT is fond of throwing at you is the pronoun number error, in which a plural pronoun replaces a singular object or vice versa.
These sentences seem correct because they reflect the reality of how most of us talk at least some of the time, but they are incorrect in formal written English.

Here is an example:
Manuel likes his coworkers, but they do not socialize with colleagues outside of work functions.

You see the problem: the subject of the sentence, Manuel, is singular, but the rest of the sentence refers to him as they.

In a verbal conversation, it would most likely be clear that the speaker means Manuel and his wife or partner, but in written English, it’s unclear.
You’d need to fix that, looking for an answer choice that replaces they with he.

By the way, you may be thinking, wouldn’t it be easier to write, “Manuel and his partner”? The answer to that is yes, that makes sense. However, you can only adjust the underlined portion of the sentence, so you’ll have to choose the best fix for that.

Modifiers
Another common form of error is the misplaced modifier. While pronoun problems in the GMAT’s Sentence Correction section are often about a misapplied pronoun, modifiers are more often misplaced than misused.

A modifier is a phrase that modifies the subject of another phrase (almost always a noun).
Modifiers should almost always come right before or right after the subject that they’re modifying. If they aren’t, the reader could think that the modifier is describing a different noun than what was intended.

Here’s an example:
Eating everything in sight, Jennifer tried to snap a photo of the black bear.
The sentence is trying to say that Jennifer tried to take a photo of a black bear who was eating everything in sight, but as you can see, the misplaced modifier makes it sound as if Jennifer was the one who couldn’t stop eating!

Although Jennifer is the subject of the sentence, the black bear is the subject of the modifier, so it should read like this:
Jennifer tried to snap a photo of the black bear eating everything in sight.
This isn’t the best sentence of all time, but it is certainly much more clear and correct.

Sentences with this type of error often happen in first drafts, before the writer has gone back to smooth out his or her writing. But because the meaning is clear to the writer, sometimes this type of sentence slips by a revision.
Luckily for you, these errors are much easier to catch when you aren’t the author!

Here are a few more misplaced modifier mistakes to look out for on the GMAT:

- Adjectives:
Sad and scared, the hotel looked welcoming to our young heroine.
Clearly, the adjectives sad and scared are supposed to modify our young heroine, not the hotel.

- Adjectival Phrases:
A cook with a master’s degree in criminology, the food made by Jack Smith was exquisite.
Here, the adjectival phrase A cook with a master’s degree in criminology is describing Jack Smith, not the food.

- A Participial Phrase Introduced with a Preposition:
After swimming for hours, the cabin on the shoreline finally was in Wei’s sight.
The phrase After swimming for hours modifies Wei, not the cabin.

Don’t be turned off by the grammatical labels above. If it makes you queasy to think of words like “a participial phrase,” then don’t!
Just know to look for what the underlined portion of the sentence is referring to, and then check to make sure it is in the right place to modify the noun it describes.

Parallelism
While parallelism is not as common a mistake to be corrected on the GMAT Verbal, it is one that is tricky to spot.

Many people don’t understand the rules behind parallelism and thus do not know what to fix on the test.
It’s very easy to read through a sentence with a parallelism error and assume that A is the right choice—that is, that the sentence has no mistakes. Be on guard that you don’t flub this type of question.

Let’s take a look at the rules, first.
Parallelism is a principle of formal written American English that states that if a sentence presents multiple related items or phrases, then each of those items or phrases should be presented in parallel grammatical structures.

The key here is that idea of parallelism: everything should get listed in the same way.

Looking at a few examples will help you understand this better.

Rules of parallelism are so often violated that we barely notice them. That makes this type of question especially challenging. Stay alert for them.

The most common GMAT question about this grammatical idea presents items in a list and asks you to decide whether they are presented in parallel form. Here’s what we mean:
Meredith, an award-winning scientist, is known for her research into blood clotting, anatomical intervention, and the applying of sutures to more efficiently heal wounds.

The list has a problem: the first two items in the list are nouns (blood clotting, anatomical intervention), but the third is a gerund (applying of sutures …). If you don’t know what a gerund is, don’t worry about it. Instead, just look at the list: two nouns, followed by a phrase beginning with a verb. They’re not parallel.

This would be a better form of the same sentence:
Meredith, an award-winning scientist, is known for her research into blood clotting, anatomical intervention, and the application of sutures to more efficiently heal wounds.

Here, application of sutures is now in noun format, and the entire sentence is parallel.

This type of error in a list doesn’t only happen with a verb inserted into a list of nouns. The nonparallel structure could be a list of verbs with a misplaced noun:
Grace, a dedicated teacher, is always taking her students to plays, inviting them on hikes, and she makes it a point to talk to their parents at least once a week.

As you can see, the error here is she makes it a point …, which doesn’t fit with the other two parts of the list. They are in verb format, so it should be too. The sentence should be something more like this:
Grace, a dedicated teacher, is always taking her students to plays, inviting them on hikes, and talking to their parents at least once a week.

While the mistake in parallelism is most commonly made in the last part of the sentence, after the and or or, it can appear anywhere, so read very carefully before deciding there’s no error in a sentence that contains a list!

Along with list errors, parallelism can trip you up in another kind of sentence.

The GMAT is also fond of two-part sentences in which the first half creates an expectation that the second half will be similarly constructed.

Here’s an example of a poorly formed sentence of this type:
To say that Gloria is an exceptional mother is giving credit where credit is due.

We know: that sentence sounds perfectly fine to the ear. But it is technically incorrect. Because the sentence begins with the infinitive (To say …), the rest of the sentence should take that form as well:
To say that Gloria is an exceptional mother is to give credit where credit is due.

The best advice we can give you on this kind of question is that when you see a sentence with a list or a two-part structure, you can be fairly sure that there’s going to be a parallelism error. Look carefully for it!

Idiomatic Expressions
This type of question is a real doozy. There are thousands of idiomatic constructions (meaning the specific ways we match words together, often comparative words and/or prepositions) in the English language, and there’s no way to prep you for all of them. 

The further bad news is that there aren’t any rules guiding idiomatic expressions, so if you run into one that you don’t know on the GMAT, you’ll be stuck with choosing the answer that sounds right.
That said, there’s good news, too: you WILL be familiar with many idiomatic expressions.
Also, if you know the expression, they’re not hard to figure out: if they sound correct, they’re correct, and if not, the answer choice that you need should be immediately apparent.

More good news: with only 15 Sentence Correction question per GMAT, there’s a good chance that the questions you receive about idiomatic expressions will be on familiar terms.

Here’s an example of an idiomatic expression question:
Since I don’t like football, I would prefer tickets to the Pirates rather with the Steelers.

The chances are pretty good that you immediately thought, wait, the answer should be “rather than.” All you would then need to do is choose that expression from the answer choices.

Idiomatic expressions aren’t colloquialisms, that is, regional sayings like “I just about fell out.” The GMAT isn’t interested in those, but in the broader range of quirks in American English.
As you can tell, this type of question responds particularly well to being mouthed so that you have a sense of what it would sound like aloud.

It only takes one read-through to know that “rather with” sounds very awkward.

Here’s a list of idiomatic expressions you can look for on the test:
According to
Appear to
As great as
As good as, or better than
Attributed to
Based on
Because of
Choose from
Conclude from
Contribute to
A debate over
Defined as
Determined by
A dispute over
Different from
In danger of
In regard to
Not only … but also
Prohibit from
Rather than
Regard as
Result of
See … as
Subject to
Think of … as

False Comparisons
You’re no doubt familiar with the old phrase “comparing apples and oranges.” Well, keep that in mind for the next type of question you can find on the GMAT, which looks for incorrect, or invalid, comparisons.

There are two kinds of this question.

The first compares two things that are not comparable.

Here is an example:
The sweaters stored in this drawer are larger than the other drawer.

Now, of course, we understand that the writer of the sentence intends to say that the sweaters in this drawer are larger than the sweaters stored in the other drawer. But the sentence doesn’t actually say that; instead, it compares the sweaters to the other drawer. To fix the sentence, you’ll have to fix the underlined portion to better reflect the actual comparison.

The sentence should be something like this:
The sweaters stored in this drawer are larger than those stored in the other drawer.

Nouns are not the only false comparisons, which leads us to our second type of false comparison question, which incorrectly compares actions:
After visiting the zoo, Gretel and I agreed that elephants move more gracefully than ostriches.

We know, we know. The example above sounds exactly like something you would say. That’s the trick with these questions, because formal written English doesn’t match the way we speak. Although it may seem silly, the above is actually a false comparison because it is comparing how elephants move to ostriches.

Here’s the correct sentence:
After visiting the zoo, Gretel and I agree that elephants move more gracefully than ostriches move.

The way this type of sentence violates our “if it sounds right, it probably is right” guideline is why we’ve particularly pointed it out to you. Be alert for it and the other false comparisons on the test.

Words to watch out for include like, as, than, similar to, and any other construction that shows a comparison is being made.

Quantity
Another tricky, and possibly unfamiliar, form of Sentence Correction question is the sentence that describes quantity.

Even if you learned these rules in school, you may not remember them now, or often hear people employ these words with complete accuracy. Let’s review them.

Basically, English has a number of different words for quantity, and those words are split between those that describe quantities of two and those that describe quantities of more than two.

Here’s a table of those words:

Thus, if you have five answer choices, you choose among those choices. But if you’re only trying to decide whether to choose B or D, you would choose between them. Similarly:
I’m trying to decide who is the better of the two singers who auditioned, because I want to choose the best of all the people who tried out.

We often use these words interchangeably when speaking, but in written English, they should be used with more care. It’s worth your time to memorize the table above.

There’s another kind of quantity question, which asks you to look at the distinction between countable and noncountable items.

The distinction is instinctive: if you would usually be able to count the number of items, then it’s countable; if not, you wouldn’t.

So, for example, the number of people in your car is countable, while the amount of traffic is noncountable.

The kind of number you are working with determines which kind of words about quantity you should use.

Here’s a quick overview:

And here are a couple of example sentences:
Madeline gave me fewer cookies than she gave Matteo.
There wasn’t much discussion about the amount of work we had to do before we continued.

In one of those quirks of English that can drive you crazy, while there are different words for smaller quantities, depending on whether they are countable or noncountable, there’s only one word for a greater number or larger amount for both countable and noncountable quantities. That word?

More.
It took us more time than we expected, but we were able to buy more towels at the sale.

Look at the reverse of the above:
It took us less time than we expected, and we were able to buy fewer towels at the sale.

English is a puzzling language. Just be ready for this mistake on test! When you see numbers or quantities—really, any of the words in the tables above—that should be a warning to you that there’s likely a mistake ahead.

Rare Errors

They are not very likely to be the main question, but they may help you eliminate answer choices.

- Split Infinitives: They look like this:
To carefully pick out the crab meat
To angrily complain about the service

These are technically incorrect, because they split the infinitive (To … [verb]) with an adverb.
Do not choose an answer choice that splits the infinitive.

The two most frequently cited grammatical rules are (1) not to end a sentence with a preposition and (2) not to split infinitives.

Interestingly, while the GMAT is less concerned about the first (more on that soon), it is definitely interested in catching you on the latter.

- The Subjunctive Mood: This verb tense expresses things that the speaker or writer wishes were true, but which are not true, as in this sentence:
If Kate were younger, she would qualify for that award.

The wish is in the first part: were Kate younger than she is, which is impossible to achieve, something could have happened.

Every once in a while, the GMAT will try to trip you up with a sentence like this:
If Jim was a nice guy, he would have asked for forgiveness.

Seems OK, right? Well, the subjunctive verb is always were, no matter how many people or things make up the subject. So it should read:
If Jim were a nice guy, he would have asked for forgiveness.

- Possessives: Sometimes the GMAT will test you to see if you use possessives properly. The one that’s most likely to trip you up is it’s.

Remember that it is = it’s.

If you want to say “something belonging to it,” write it as in this example:
The dog chewed its leash when left alone.

- Terminal Prepositions: This grammatical rule has somewhat fallen out of favor lately, but some grammarians say that you shouldn’t end a sentence with a preposition:
She didn’t know who to go with.
He wasn’t sure what to do as there wasn’t anyone to talk to.

Because this rule is no longer so steadfastly enforced, it’s unlikely you’ll see it as a main question. However, we suggest avoiding any answer choices that force the sentence to end in a preposition.

Other Answers to Avoid
Here are a few more tips about which answers to avoid. We suggest avoiding any answer that includes the word being if it isn’t referring to a human being.

In conversation, people are fond of using being incorrectly as follows:

Being that I’m the head teacher, I need to get there first.
She was early for the interview, being that she was nervous.

These sentences aren’t exactly wrong, but they’re not great. Don’t choose them.

Also, avoid complex verb constructions like this one:
Marie will have been teaching at the school for 20 years next year.

A better choice is:
Marie has been a teacher at the school for 20 years next year.

Try to choose active verb constructions in your answer.

Avoid:
The book was moved.

And choose:
Andrew moved the book.

Again, these aren’t ironclad rules. There might be a question or two that requires a passive verb, or the use of being in some odd way. But overall, these are good guidelines, especially when trying to choose between two answer choices that seem equally correct. R

emember, Sentence Correction questions are asking you to consider effective expression as well as correctness.

It stands to reason that you may need to ask yourself, “What is the most effective way to state this, as well as the grammatically correct way?”