GMAT Sentence Correction: Master Parallel Structure Flawlessly

GMAT Sentence Correction: Master Parallel Structure Flawlessly

Hey there! If you’re gearing up for the GMAT, you’ve probably heard the term “parallel structure” thrown around. Maybe it sounds a bit intimidating, like some super complex grammar rule only English professors understand. But what if I told you it’s actually one of the most intuitive and logical concepts on the GMAT Sentence Correction section? It’s true! And once you truly ‘get’ it, you’ll start seeing those tricky questions in a whole new light. Think of this as our little coffee shop chat about making parallel structure your absolute superpower for the exam.

So, what exactly is parallel structure? At its heart, it’s all about balance and consistency. Imagine you’re building a fence. You wouldn’t use wooden planks, then suddenly switch to brick, and then throw in some chicken wire, right? No, you’d want all your fence posts, rails, and pickets to be similar in form and function. That’s essentially what parallel structure demands in a sentence: if you’re listing items, comparing things, or joining clauses, they all need to follow the same grammatical pattern. It makes your writing clear, elegant, and much easier to read.

The GMAT absolutely loves parallel structure. Why? Because it tests your ability to spot logical inconsistencies and awkward phrasing. It’s not just about knowing obscure grammar rules; it’s about understanding how language works best to convey meaning without ambiguity. When a sentence lacks parallelism, it feels clunky, confusing, and just plain wrong. And the GMAT knows you can feel that too, even if you can’t always pinpoint why it feels wrong. Our goal today is to give you the tools to pinpoint it every single time.

The Golden Rule: Like with Like

This is the core principle you need to engrave in your brain: always connect like elements with like elements. Think of it as matching pairs. If you start with a noun, every other item in that series should also be a noun. If you use an -ing verb, then all subsequent verbs in the same structure should also be -ing verbs. Simple, right? But the GMAT will try to trick you by mixing and matching, hoping you won’t notice the subtle shift.

Let’s look at a quick example to drive this home:

Incorrect: Sarah loves to sing, dancing, and cooking.

Do you hear how “to sing” just doesn’t quite fit with “dancing” and “cooking”? “Dancing” and “cooking” are gerunds (verbs acting as nouns, ending in -ing). “To sing” is an infinitive. They’re not “like elements.”

Correct: Sarah loves singing, dancing, and cooking.

Ah, much better! Now all three are gerunds. Or, we could go with infinitives:

Correct: Sarah loves to sing, to dance, and to cook.

See? Consistency is key. You pick a form, and you stick to it for all the items in that parallel construction.

Common Places Parallel Structure Hides (and How to Uncover It)

Parallelism isn’t just about simple lists. The GMAT uses it in several sneaky ways. Let’s break down the most common scenarios.

1. Lists and Series (The Obvious One)

This is where you’ll most often spot parallel structure errors. Whenever you see three or more items separated by commas and joined by a conjunction (like “and” or “or”), your parallel radar should go off immediately. These items absolutely must match grammatically.

• Incorrect: The company specializes in developing software, consulting for clients, and provides support.

  Here, “developing software” and “consulting for clients” are participial phrases (starting with -ing verbs). But “provides support” is a complete verb phrase. It breaks the pattern.

• Correct: The company specializes in developing software, consulting for clients, and providing support.

  Now all three are parallel participial phrases. Perfect!

2. Comparisons (Using “Than” or “As”)

When you’re comparing two things, those two things need to be grammatically equivalent. You can’t compare apples to the act of peeling oranges. It just doesn’t make sense.

• Incorrect: Running a marathon is harder than to swim a mile.

  Here, “Running a marathon” is a gerund phrase. “To swim a mile” is an infinitive phrase. Not parallel.

• Correct: Running a marathon is harder than swimming a mile.

  Both are gerund phrases. Or:

• Correct: To run a marathon is harder than to swim a mile.

  Both are infinitive phrases. See the consistency?

This applies to comparisons using “as… as” as well:

• Incorrect: His performance was as impressive as how he handled the pressure.

• Correct: His performance was as impressive as his handling of the pressure.

3. Correlative Conjunctions (The “Both… And” Gang)

These are super common on the GMAT, and they are huge red flags for parallel structure. Correlative conjunctions come in pairs, and whatever grammatical structure follows the first part of the pair must follow the second part.

The main correlative conjunctions you need to know are:

• both… and…
• either… or…
• neither… nor…
• not only… but also…
• whether… or…
• from… to…

Let’s look at some examples:

• Incorrect: John is not only a talented musician but also writes poetry.

  After “not only” we have a noun phrase (“a talented musician”). After “but also” we have a verb phrase (“writes poetry”). They don’t match!

• Correct: John is not only a talented musician but also a gifted poet.

  Now both are noun phrases.

• Correct: John not only plays music beautifully but also writes poetry eloquently.

  Now both are verb phrases.

Another one:

• Incorrect: The committee decided either to approve the budget or that they would delay the vote.

  After “either” we have an infinitive phrase (“to approve the budget”). After “or” we have a full clause (“that they would delay the vote”). No parallelism!

• Correct: The committee decided either to approve the budget or to delay the vote.

  Now both are infinitive phrases. Spot on!

4. Verbs in a Series (Matching Tenses and Forms)

This is similar to lists, but specifically for actions. If a subject performs multiple actions, those verbs should usually be in the same tense and form.

• Incorrect: She woke up early, ate breakfast quickly, and then went to work.

  Wait, this one looks pretty good, doesn’t it? “Woke up,” “ate,” “went” are all simple past tense. This is actually correct! The GMAT will sometimes present you with correct sentences to make you second-guess yourself.

Let’s try a truly incorrect one:

• Incorrect: She woke up early, eating breakfast quickly, and then went to work.

  Here, “woke up” and “went” are simple past verbs. But “eating breakfast quickly” is a participial phrase. It breaks the parallel structure.

• Correct: She woke up early, ate breakfast quickly, and then went to work.

  All simple past verbs. Flawless.

5. Clauses in a Series (When Entire Statements Need to Match)

Sometimes, what needs to be parallel isn’t just a word or a phrase, but entire clauses (parts of a sentence that contain a subject and a verb). This is a bit more advanced, but the principle remains the same.

• Incorrect: The report stated that the economy was growing, that inflation was under control, and prices would remain stable.

  Notice the “that” at the beginning of the first two clauses? It’s a signal. The third clause (“prices would remain stable”) is missing its “that.” While sometimes “that” can be omitted for conciseness, in a parallel structure, its presence or absence needs to be consistent.

• Correct: The report stated that the economy was growing, that inflation was under control, and that prices would remain stable.

  Now, all three clauses begin with “that,” making them perfectly parallel.

Your Action Plan: How to Spot and Fix Parallelism Errors

Alright, so we’ve covered the what and the where. Now, let’s talk about the how. How do you actually find these errors quickly and confidently on test day?

1. Listen to Your Ear (But Don’t Trust it Blindly)

Read the sentence aloud. Does it sound awkward? Does one part seem to stick out? Your ear is a surprisingly good initial detector. However, don’t rely solely on it, because the GMAT is designed to make subtle errors sound plausible.

2. Identify the “Trigger” Words

Look for the parallelism signals we discussed:

• Conjunctions: and, or, but
• Comparison words: than, as
• Correlative conjunctions: both… and, either… or, not only… but also, etc.

These words are like little flags telling you, “Hey, check for parallelism here!”

3. Locate the Items Being Compared or Listed

Once you find a trigger, identify the elements it’s connecting. Put brackets around them if it helps. For example: “She loves [singing], [dancing], and [to cook].” Immediately, you’ll see the mismatch.

4. Demand Grammatical Consistency

Are they all nouns? All verbs? All infinitive phrases? All gerund phrases? All clauses? They must be the same. If they’re not, you’ve found your error.

5. Don’t Forget About Opening Words (Prepositions, Articles, “To”)

Sometimes the parallelism isn’t just about the main word, but the little words that introduce it. If you repeat a preposition (“in the morning, in the afternoon, and in the evening”), that’s fine. If you omit it consistently (“in the morning, afternoon, and evening”), that’s also fine. But if you mix (“in the morning, afternoon, and in the evening”), that’s a problem. Be consistent!

Example:

Incorrect: The scientist experimented with microscopes, test tubes, and using a new chemical solution.

Here, “microscopes” and “test tubes” are nouns. “using a new chemical solution” is a gerund phrase. This creates an issue.

Correct: The scientist experimented with microscopes, test tubes, and new chemical solutions.

Now all three are nouns. Or, if you want to keep the action:

Correct: The scientist experimented by using microscopes, handling test tubes, and applying a new chemical solution.

Now all three are parallel gerund phrases, following the preposition “by.”

Beyond the Rules: Why This Matters for Your GMAT Score

Mastering parallel structure isn’t just about getting a few Sentence Correction questions right. It’s about developing a keen eye for grammatical precision and logical construction, skills that permeate every section of the GMAT, especially Critical Reasoning and Reading Comprehension. When you can quickly dissect a sentence to understand its underlying structure, you’re not just identifying errors; you’re grasping meaning at a deeper level.

Think about it: the GMAT wants to see if you can communicate clearly and concisely, like a business professional. Parallel structure is a cornerstone of clear, professional communication. It demonstrates an ability to organize thoughts logically and present information elegantly. The more you practice identifying and correcting these flaws, the more naturally you’ll start to recognize them, even in sentences that might seem complex at first glance. It becomes less about memorizing rules and more about an intuitive understanding of effective language.

So, take a deep breath. Parallel structure is a friend, not a foe. It’s a consistent, predictable pattern that the GMAT tests relentlessly. Once you train your eye to spot those trigger words and demand grammatical consistency from everything connected to them, you’ll find yourself breezing through a whole category of Sentence Correction questions. Keep practicing with official GMAT materials, break down each option, and always ask yourself: “Are these elements truly ‘like with like’?” You’ve got this!

—
📚 ¿Necesitas preparación personalizada?

Soy Claudio Hurtado, tutor especializado en preparación online para:
• GMAT QUANT
• GRE QUANT
• SAT QUANT
• EA QUANT
• FRM QUANT

Ofrezco tutorías personalizadas, adaptadas a tu ritmo y objetivos.

🌐 Visita mis sitios web:
• https://clasesgmat.es (para España)
• https://gmatchile.cl (para Chile)

📧 Contáctame: clasesgmatchile@gmail.com
📱 WhatsApp: +56937780070