How do your Sentence Correction skills stack up when it comes to parallel structure?  As this article explains, items in a list must be in parallel form, as must items being compared.  “Parallel” means that nouns go with nouns and verbs go with verbs.  Verbs must be in the same tense or form, and prepositions or other “helping” words must be parallel as well.  Take this GMAT-style question, for example:

The restaurant’s manager reported an increase in customers during the month of June, as much because of its business of the month before being so slow as that more tourists travel through the area in the summer.

1. a. of its business of the month before being so slow as that
2. b. of its business the month before having been slow as because
3. c. of its business the month before being as slow as because
4. d. its business the month before had been so slow as because
5. e. its business of the month before was as slow as that

In terms of parallelism, if you choose to say “because of its business…” you will need to use the parallel phrase “as because of more tourists travel…”  And “because of more tourists travel” doesn’t make sense; therefore, we can eliminate all the choices that begin with “of,” which leaves us with only the final two choices.  The “because” immediately before the underlined portion of the sentence leaves us with no choice but to use a “because” before “more tourists.”  Choosing ‘d’ as the correct answer, we end up with a parallel phrase: “as much because x as because y.”

A more common parallelism issue is verb form.  Gerunds need to be paired with gerunds, past tense verbs with other past tense verbs, and so on.  Let’s look at an example of that issue:

The recent decline in bus commuter ridership has left the system underfunded, to cause the number of buses running during peak times to drop, and prompts concerns that further service cuts may lead to the collapse of the city’s entire public transportation system.

1. a. to cause the number of buses running during peak times to drop, and prompts
2. b. causing the number of buses running during peak times to drop and prompting
3. c. to cause reductions in the number of buses running during peak times and prompt
4. d. to cause the number of buses running during peak times to be reduced, and prompted
5. e. causing a reduction in the number of buses running during peak times and prompting

So what do you think, Grockit readers?  Note your choice in the comments section, as well as your reasoning, and we’ll post the correct answer, as well as an explanation, in an upcoming article.