GMAT Sentence Correction: Modifying Phrases

On the GMAT, sentences that employ a modifying phrase incorrectly are a common trick. A modifying phrase is one that describes something. Here are a couple of examples of uncomplicated sentences that incorrectly use modifying phrases:
Sentence A:

Ever since her paw was crushed in the front door, Mrs. Benson has been worried about Muffin, her pet cat.

Sentence A starts off with the modifying phrase “Ever since her paw was crushed in the front door,” and then talks about Mrs. Benson and her worry for her cat. But Mrs. Benson sounds like a person, and as a person, she probably doesn’t have a paw to be crushed. It’s MUCH more likely that Muffin’s paw got crushed, causing Mrs. Benson’s worry. This sentence needs to be corrected to put the modifying phrase next to the item it modifies. Here are a couple of ways that we can do that, depending on where the sentence’s underlining is placed:
Sentence A1:

Ever since her paw was crushed in the front door, Mrs. Benson has been worried about Muffin, her pet cat.

If the modifying phrase isn’t underlined, we don’t have the opportunity to fix it– but we can rearrange the rest of the sentence so that the thing that is modified (Muffin the cat) is placed next to that phrase. The corrected version might look like this:
Sentence A2:

Ever since her paw was crushed in the front door, Mrs. Benson’s pet cat Muffin has been a source of worry to her owner.

By turning “Mrs. Benson” into the possessive “Mrs. Benson’s,” and then placing “pet cat Muffin” right behind it, we turn “Mrs. Benson’s pet cat Muffin” into the sentence’s subject and put the modifying phrase right next to the thing it modifies, where it belongs. But what if it’s the modifying phrase itself that is underlined? Here’s an example of how that would look and how it would be fixed:
Sentence A3:

Ever since her paw was crushed in the front door, Mrs. Benson has been worried about Muffin, her pet cat.

Sentence A4:

Ever since she saw the poor feline’s paw crushed in the front door, Mrs. Benson has been worried about Muffin, her pet cat.

In Sentence A3, the modifying phrase uses the pronoun “her,” which could technically refer to either Mrs. Benson or to Muffin. That makes the modifying phase’s placement confusing. By changing the modifying phrase so that it clearly identifies both “she” and “the poor feline,” and describes Mrs. Benson, we correct any confusion from the placement of the modifying phrase.
Let’s try another, slightly more difficult example:
Sentence B:

Snowstorms are common in the Midwest, which is a frequent cause of school cancellations and traffic accidents in the winter months.

The modifying phrase here is “which is a frequent cause of school cancellations and traffic accidents in the winter months.” But that’s placed next to “the Midwest,” and the location isn’t what causes the winter weather problems; the snowstorms are causing the problems. So the sentence needs to be corrected to account for that. Here are a couple of ways to do that:
Sentence B:

Snowstorms are common in the Midwest, which is a frequent cause of school cancellations and traffic accidents in the winter months.

Sentence B2:

Snowstorms, which are common in the Midwest, are a frequent cause of school cancellations and traffic accidents in the winter months.

Here we’ve made “[s]nowstorms” the clear subject of the sentence, and changed the structure of the sentence so that there is a parenthetical phrase describing snowstorms immediately after that subject.
Sentence B:

Snowstorms are common in the Midwest, which is a frequent cause of school cancellations and traffic accidents in the winter months.

Sentence B4:

Snowstorms are common in the Midwest, where residents frequently face school cancellations and traffic accidents in the winter months.

In this version of Sentence B, the modifying phrase has been reworded so that it now clearly describes the Midwest, not the snowstorms.
In all of the examples above, the central issue in identifying the proper sentence correction is the placement of the underline. Be very conscious of that in your reading; anytime you see a modifying phrase, you should immediately check to make sure that it is correctly placed to modify its subject, and then determine what you can change, based on the underlining. And remember, there’s almost always more than one way to reach the goal of grammatical correctness. If your predicted “fix” isn’t among the answer choices, keep an open mind when you evaluate the choices to see which one accomplishes the goal of correct modifying phrase placement.