While solving Sentence Correction questions, a lot of test-takers rely on their ear to give them the answer, which is why one often hears the phrase, “this option doesn’t sound right”.

While the ear does play a very important role, it more important to listen with a purpose. When it comes to Standard Written English, which is what is tested on the GMAT as well as other tests, it is important to listen for structure.

Different sentences have different structures based on their construction. In this post, let us look at one type of structure, comparatives, with help of a sentence correction question from the Official Guide (OG).

Unlike the buildings in Mesopotamian cities, which were arranged haphazardly, the same basic plan was followed for all cities of the Indus Valley: with houses laid out on a north-south, east-west grid, and houses and walls were built of standard-size bricks.

(1) the buildings in Mesopotamian cities, which were arranged haphazardly, the same basic plan was followed for all cities of the Indus Valley: with houses
(2) the buildings in Mesopotamian cities, which were haphazard in arrangement, the same basic plan was used in all cities of the Indus Valley: houses were
(3) the arrangement of buildings in Mesopotamian cities, which were haphazard, the cities of the Indus Valley all followed the same basic plan: houses
(4) Mesopotamian cities, in which buildings were arranged haphazardly, the cities of the Indus Valley all followed the same basic plan: houses were
(5) Mesopotamian cities, which had buildings that were arranged haphazardly, the same basic plan was used for all cities in the Indus Valley: houses that were

By GMAT standards this is quite long sentence and would cost most test-takers more than the average time available, 1:49 seconds. But if one listens to the structure it can be solved in less than a minute.

In all  sentences that start with Unlike, Like or In contrast to, basically sentences that involve a comparison, we have to compare two similar things or apples v apples.

In the sentence above, buildings in Mesopotamian cities are compared to the plan in the Indus Valley; the correct option should compare apples with apples.

(B) makes the same faulty comparison as (A).
(C) compares arrangement with cities
(E) compares cities with plan
Only (D) compares cities with cities.

It is one of those questions that can be solved in under 45 seconds since it does not involve selecting between two close options. Test-takers would save a lot of time that would be otherwise be spent in unnecessarily reading each option in its entirety by just checking for the rule. In the next post we will discuss a set of GMAT questions that follow this rule before we go on to the next rule.