GMAT Ninja's Sentence Correction Guide for Beginners

GMAT Ninja's Sentence Correction Guide for Beginners


This thread is dedicated to everybody who has asked this question during our Wednesday verbal chats:

“The moment we see a SC question. What should be the approach?”

If you open 20 different GMAT test-prep books, you’ll probably see 20 different answers to that question. And you’ll also see 4000 different idioms, 392 different grammar rules, and 10,000 kilograms of grammar jargon. Approximately.

And all of that stuff can be great: you’ll definitely need a basic understanding of grammar, or else sentence correction will be pretty tough. But there’s an endless mountain of SC advice out there, and it can be hard to know where to begin. If you’ve already memorized dozens of grammar rules and hundreds of idioms, that’s great – but memorizing piles of rules won’t always help you figure out what, exactly, you should do when an SC question pops up on the screen.

So here’s our attempt to cut through the noise with a simple, effective “baseline” approach to GMAT sentence correction. This post comes with our usual friendly warning: like our beginner’s guides to CR and RC, this one is long!


But first... a story

Once upon a time, I attended a psychometrics conference that was dominated by academics and geeky employees of standardized testing organizations, including ETS (makers of the GRE and TOEFL) and GMAC (creators of your beloved GMAT). I watched a presentation by a high-ranking GMAT psychometrician, who discussed… well, nevermind that part, I’ll put you right to sleep with that crap.

Anyway, somebody in the audience asked about the “math section of the GMAT.” The GMAT psychometrician interrupted him politely: “Pardon me,” the GMAT guy said, “there is no math section on the GMAT. There’s only quantitative reasoning.”

I probably rolled my eyes. “What a dick,” I thought, “why would he make a big deal out of that? It’s math. Whatever, dude.”

Sure, maybe the GMAT psychometrician had chosen a less-than-ideal time to make a fuss about terminology, but he absolutely had a point. If you think of the quant section as only “math”, you might ignore the fact that there’s a ton of logic rolled into GMAT quant problems. You won’t succeed if you’re just regurgitating math formulas: you have to actually do some reasoning to get an elite score on the GMAT quant section.

The same thing is true of the verbal section of the exam – perhaps even more so than on the quant section. You can’t just regurgitate rules and formulas if you want to succeed on GMAT verbal. And there is no “reading and grammar” section on the GMAT: it’s called “verbal reasoning.”

And unfortunately, to reach an elite level on SC, you have to think of it as a “reasoning” task – not just a grammatical one.

So yes, you need to understand grammar in order to achieve elite results on GMAT SC. But grammar alone won’t get you to a great GMAT score.


Figuring out what’s really important

The key to success on GMAT SC isn’t knowing every single rule in the English language. You need to know enough about the most frequently tested rules – and then the really important thing is knowing what to prioritize when an SC question appears on the screen.

Let’s face it: the English language sometimes feels infinite, regardless of whether you’re a native speaker or a non-native speaker. English offers an endless supply of exciting-sounding things like gerunds, adjectival modifiers, progressive tenses, and absolute phrases. English even has a glorious array of around 25,000 idioms – which, for whatever it’s worth, you probably don’t want to memorize.

If you really do want to learn all of that stuff, go for it. But here’s how it can hurt you on the GMAT: when you see an SC question, do you start by thinking about a random grammar rule, or are you able to cut straight to the MOST IMPORTANT things in the sentence? Or does your brain just logjam entirely, because it’s been overstuffed with rules and jargon and idioms?

So if you’ve already maximized your grammar knowledge – without actually maximizing your GMAT SC results – then you probably need to simplify your approach, and focus on the most important things first. To succeed on GMAT SC, you’ll want to begin by executing flawlessly on two steps.


Step 1: DEFINITE errors first

The first step you should always take on SC is eliminating any answer choices that contain DEFINITE errors.

What do we mean by that? If you’re certain, for example, that a pronoun has no antecedent, or that the subject of the sentence doesn’t agree with the verb, or that a modifier is misplaced... then cross the offending answer choice out. Sounds simple enough, right?

But I see mistakes with this process literally every single day: some test-takers will begin by eliminating SC answer choices because they “don’t sound good” or because they’re “wordy” or because “the comparison sounds awkward.” If you start with any of these things – all of which are basically opinions and not rules – you’re making a huge mistake.

Similarly, if you start by eliminating answer choices based on a “grammar rule” that you aren’t certain is actually a rule, that’s a big mistake, too. Be conservative at first: if you don’t know for CERTAIN that an answer choice is wrong, keep it until you really are certain.

So the key is to start with the most straightforward, frequently tested rules. The following are topics that will give you the most bang for your buck, because they are either based on very mechanical rules – or because the GMAT simply loves to test them:

1. pronouns (it, they, that, those)
2. modifiers (that, which, “-ing”, “-ed”, etc.)
3. parallelism, including special parallelism triggers (both/and, either/or, not/but)
4. basic comparisons, especially “like,” “unlike”, and “as”
5. subject-verb agreement
6. verb tenses, especially past perfect tense
7. a few other minor-but-straightforward topics: semicolons, “due to”, and countable vs. non-countable modifiers

As a first step to success on GMAT SC, you’ll want to understand these topics thoroughly – and more importantly, you’ll want to make sure that these jump off the page at you whenever you see them. If you fail to notice “it” or “they” or “which” or “that” or “and” when they appear in a sentence, you might miss some very easy questions. And on an adaptive test, you’re in big trouble if you miss even a few easy questions.

If you master these seven topics, you’ll be able to eliminate roughly half of the wrong answer choices on the GMAT. To be fair, that’s just a very rough estimate: some official questions, like this one and this one, are based solely on those seven topics. But in other SC questions – including this one and this one – those seven topics are lamentably useless.

So these seven topics aren’t everything. But they’re always the most efficient place to start. (And don’t worry: we’ll eventually cover them all in our Topic of the Week series, and there are plenty of links at the end of this article to help get you started.)


Step 2: compare remaining choices based on meaning

OK, so what do you do once you’ve eliminated everything you can based on clear, definite rules?

Remember our mantra: the section is called “verbal reasoning,” not “grammar and reading.” So once you’ve found every DEFINITE grammar error you can, your next job is to figure out how to make the structure of the sentence match the meaning.

Here’s the basic idea: compare the remaining pairs of answer choices, and identify the EXACT differences between each pair. Then think about whether those differences are going to impact the meaning in some way. Of course, that part gets really subtle and tricky – and it’s different on every question.

Here are a few shortened examples, adapted from official GMAT questions:

Companies in the United States are providing job training and general education for nearly eight million people, about equal to those who are enrolled in the nation’s four-year colleges and universities.

1. equal to those who are enrolled in
2. as many as are enrolled in

Option #1 is literally saying that the 8 million people in job training programs are “equal to the people who are enrolled in four-year colleges and universities.” That’s not grammatically wrong at all! And it seems to be a very nice sentiment about equality among people with different educational backgrounds.

But that’s really not what the sentence is trying to say: in option #2, it’s clear that we’re comparing the number of people in each group, not making a statement about how one group of people is “equal to” the other.

Here, have another one:

Some buildings that were destroyed or heavily damaged in the earthquake last year had been constructed in violation of the city's building code.

1. Some buildings that were destroyed or heavily damaged in the earthquake last year had been
2. Last year some of the buildings that were destroyed or heavily damaged in the earthquake had been

This one is interesting, because the only real difference is the placement of the phrase “last year.” In option #1, “last year” is right next to “earthquake,” and it seems to be telling us that the earthquake occurred last year. That seems reasonable.

But option #2 subtly expresses the wrong idea. “Last year” is right at the beginning of the sentence, suggesting that the entire first clause is the thing that happened last year: “some of the buildings… [modifier blah blah]… had been constructed in violation of the city’s building code.” But that doesn’t make sense: the buildings weren’t constructed last year.

Let’s do one more:

In the mid-1920’s the Hawthorne Works of the Western Electric Company was the scene of an intensive series of experiments that investigated changes in working conditions’ effects on workers’ performance.

1. that investigated changes in working conditions’ effects on workers’ performance
2. investigating the effects that changes in working conditions would have on workers’ performance

This one is also pretty subtle. There are plenty of little differences here (“that investigated changes” vs. “investigating”; use of conditional “would have”), and it’s easy to get distracted.

But here’s the important difference that really impacts the meaning: option #1 says that the company investigated changes in the (working conditions’) effects – not changes in the working conditions themselves. Nasty! Option #2 “sounds wordier”, but the meaning is much more reasonable: the experiments apparently changed the working conditions, and then investigated the effects of those changes on worker performance.

And we could go on and on with more examples. The bottom line: getting better at distinguishing between the meaning of two sentences is a difficult thing, since no two questions will test exactly the same content and meaning. But unfortunately, there’s no way around it: to get to an elite SC score, you’ll have to get pretty good at finding the strict, LITERAL differences in meaning between two or more answer choices.


Your ear is your enemy!

Now that we’ve discussed what you should do when you’re getting started on SC, let’s talk about what you shouldn’t do.

For starters, you should NEVER rely on your ear, unless you have absolutely no other options. When SC was first developed in the 1980s, globalization hadn’t really taken off yet, and the GMAT’s creators certainly weren’t trying to torment non-native speakers. The whole point was just to see whether test-takers could tell the difference between “correct written English” and the way educated Americans speak in real life.

In other words, SC was designed to punish test-takers who relied on their ear. And that hasn’t changed at all.

Let’s face it: a huge percentage of correct GMAT SC sentences sound like hot garbage. Many of them are just too damned long and convoluted. They’re often messy, wordy, and awkward.

And yes, the (not very useful) GMAT OG explanations often use the words “wordy” or “awkward”, but those are subjective terms. If you dismiss an answer choice based on them, you’re basically “using your ear” or relying on instincts, rather than engaging in methodical, disciplined verbal reasoning. And that’s incredibly dangerous, because what “sounds awkward” to you might not be awkward to the test-writers.

So keep your ear out of it! Remember: the section is called “verbal reasoning", not "ooh, this one sounds pretty good."


What about other grammar rules?

By now, you might be thinking something like this: “Hang on, Ninja dude. I’ve studied tons of other things, like passive voice and gerunds and idioms and punctuation. They’re useful. I’ve even read posts about them here on GMAT Club. Hey wait, Ninja guy – you WROTE some of those posts, you freaking lunatic! And now you’re saying that they don’t matter?!?”

Easy there, cowboy. I’m not saying that they don’t matter. I’m saying that if you’re just getting started with sentence correction – or if your results are stagnant after cramming tons of grammar into your head – then memorizing more rules and more jargon and more idioms won’t necessarily help.

Again, here’s what’s really important:

1. Your ability to immediately recognize the most frequently-tested rules as soon as you see any SC question, as described above. If an answer choice features a basic grammar topic, like parallelism or pronouns or modifier placement, then you absolutely can’t afford to miss it.
2. Whether you can accurately understand the EXACT differences in meaning among the remaining choices. And all of the grammar rules in the world won’t help you much with this part.

If memorizing more rules distracts you from these two tasks – or worse, just causes an epic brain logjam – then the memorization isn’t a great use of your time.

So if you want to learn additional, “minor” grammar rules and if you’re able to use them wisely, that’s great: keep going! Just don’t let your quest for more grammar knowledge distract you from the important stuff.


Don’t fall in love

You’ve heard this before, too, but it’s worth repeating: whenever you do anything on the GMAT verbal section, you should always look for four wrong answers – not one right answer. If you try to take shortcuts with this process, I promise that you’ll make mistakes, especially on relatively difficult questions.

The easiest mistake to make on GMAT SC is this: you’ll read the original sentence, and decide what you want the sentence to say in its “correct” or “ideal” form. But I have bad news: whatever you’re thinking probably won’t be an option. Again, correct answers on SC aren’t always good sentences – they’re just the least-terrible of the five options.

So we’ll say it again: don’t fall in love. Instead of looking for one wonderful, correct sentence, identify four wrong answers. You might not like the answer that remains, because it might sound like a steaming turd. But if you’ve done your job properly, it will still be the right answer.


Stick to the official stuff

You’ve undoubtedly heard this before, too: the GMAT spends between $1500 and $3000 developing every official question, and even the very best test-prep experts – including whoever writes and selects those GMAT Club verbal Questions of the Day – simply can’t compete.

So when you’re doing questions here on GMAT Club, please keep an eye on the tags that indicate the question source. You might be able to learn something from the non-official SC questions sometimes, but whenever possible, focus your SC energy on official questions.


Yes, this is about reading skill, too

If you’ve read our Ultimate RC Guide for Beginners or our Ultimate CR Guide for Beginners, you already know that strong reading skills are a prerequisite for elite CR and RC results.

The same is true for SC, albeit to a lesser degree. If you struggle to understand EXACTLY how a small change in language impacts the meaning of a sentence, then all of the test-prep strategies in the world won’t help much. Sure, you’ll be able to get mechanical, purely grammar-based questions right. And then you’ll hit a ceiling on SC, since meaning is easily half of the battle.

So if your underlying reading skills need improvement, be honest with yourself about it! And if you need to work on those skills, check out the links at the end of this post and in the Ultimate RC Guide for Beginners.


Want more?

You have questions about SC? GMAT Club has you very, very thoroughly covered:

• Live Wednesday verbal chats! Ask your questions (or read Vyshak‘s wonderful transcripts) here.
• How to improve from great (760) to incredible (780!) on SC
• An article about the GMAT’s many uses of “that”, including “that” pronouns and exceptions to the modifier “touch rule”
• GMAT Club’s YouTube page, including a video version of the article on the GMAT’s many uses of “that”
• Another video of that same weird guy babbling about advanced pronoun rules
• For more exciting GMAT modifier action, check out this Topic of the Week on ”-ing” words…
• …or this Topic of the Week on “-ed” words
• Here’s a complete collection of modifier threads by souvik101990
• An incredible master directory to official verbal questions, compiled by @carcass
• Complete collection of official SCs by @souvik101990
• Our no-BS guide to GMAT idioms
• What to do about timing on GMAT verbal
• Our beginners' guides to RC and CR
• bb’s long-running thread about the best books to read
• carcass's list of favorite magazines and periodicals
• SC Verbal question bank and directories by Carcass
• All verbal experts’ Topic of the Week threads, compiled by @carcass