Identifying and Correcting Run-On Sentences on GMAT Verbal Questions

Quarter Wit, Quarter WisdomOn the GMAT, most sentence correction questions involve compound/complex sentences with multiple phrases, clauses and modifiers. Hence it is very likely that you will see some run-on sentences on your test. In the complicated sentences that we get on the GMAT, it is very easy to overlook that we are dealing with run-on sentences.

A run-on sentence has at least two independent clauses which are not connected properly. There are various ways in which a sentence may be run-on. Here are some of the most common circumstances:

  1. When an independent clause gives a suggestion/advice/command based on what was said in the prior independent clause:

GMAT is a very tricky test, you should work hard.

Here, we should either split the two clauses into two sentences by putting in a full stop or we should put a semi colon between the two clauses.

  1. When two independent clauses are connected by a conjunctive adverb such as however, moreover, nevertheless.

My grandmother is supposed to travel tomorrow, however, she is not feeling well.

Here, we should either split the two clauses into two sentences by putting in a full stop or we should put a semi colon between the two clauses

To read more on conjunctive adverbs, check out this post.

  1. When the second of two independent clauses contains a pronoun that connects it to the first independent clause.

Marcy is thrilled, she got permission to go to the school dance.

Although these two clauses are quite brief, and the ideas are closely related, this is a run-on sentence. We need to put a full stop or a semi colon in place of the comma.

Now that we have an idea of what run-on sentences are, let’s look at a GMAT Prep question where this concept is tested extensively.

Question: The Anasazi settlements at Chaco Canyon were built on a spectacular scale with more than 75 carefully engineered structures, of up to 600 rooms each, were connected by a complex regional system of roads.

(A) with more than 75 carefully engineered structures, of up to 600 rooms each, were

(B) with more than 75 carefully engineered structures, of up to 600 rooms each,

(C) of more than 75 carefully engineered structures of up to 600 rooms, each that had been

(D) of more than 75 carefully engineered structures of up to 600 rooms and with each

(E) of more than 75 carefully engineered structures of up to 600 rooms each had been

Solution:

Consider option (A): Remove all the unnecessary elements and get the skeleton of the sentence (primarily the subject and the verbs):

The settlements were built on a spectacular scale…, were connected …

The action verb “were connected” has no subject here. If it were to have the same subject as the first clause “the Anasazi settlements”, then there should have been a conjunction joining the two clauses together. This is a run-on sentence.

Consider option (B): The problem of run-on sentence has been rectified here by using past participle instead.
The settlements were built on a spectacular scale with more than 75 carefully engineered structures, of up to 600 rooms each, connected by a complex regional system of roads.

Remove the non essential modifier “of up to 600 rooms each” and you see that the 75 carefully engineered structures were the ones connected by a complex system of roads. Now it all makes sense.

To read more about participles, check this post.

Let’s look at the other options too.

Option (C): You cannot say “built on a spectacular scale of more than 75 structures”. You need “with” instead of “of”. The same problem exists with options (D) and (E) too.

Also, in option (C), the use of past perfect “had been” is not justified.

Option (D): As discussed above, “scale of” is incorrect in option (D).
It is also illogical “and with each connected” doesn’t clarify what of each is connected by roads.

Option (E): As discussed above, “scale of” is incorrect in option (E).

Also, it is a run-on sentence.

The settlements were built on a spectacular scale of more than 75 carefully engineered structures of up to 600 rooms each had been connected by a complex regional system of roads.

The two different clauses do not even have a comma in between here. Also, the use of past perfect “had been” is not justified.

Hope you understand run-on sentences a little better now.

Karishma, a Computer Engineer with a keen interest in alternative Mathematical approaches, has mentored students in the continents of Asia, Europe and North America. She teaches the GMAT for Veritas Prep and regularly participates in content development projects such as this blog!