1.5 SAT Writing - Parallel Structure

Parallel Structure: Many students may develop ideas that are out of balance and the SAT test makers recognize this flaw. The idea is simple: when creating lists or doubling up on ideas the elements must mirror each other.  Simply put, each element in a list must wear the same uniform for parallel structure.  Take the following example:

The students enjoyed going to the movies, playing various sports, and they liked hiking in the mountains. 

Consider each group of words as its own element:

Element 1 = going to the movies Element 2 = playing various sports Element 3 = they liked hiking in the mountains

For the most part, commas separate the elements.  If you haven't noticed, this sentence contains a parallel structure error since the elements do not wear the same uniform.  Element 1 contains a correct gerund phrase as well as Element 2.  The problem occurs at Element 3 since the author uses an entire independent clause instead of matching the element to the other two.  Fixing this error is as simple as spotting the element that sticks out and changing its clothes to fit the other elements.  In this case, Element 3 should read "hiking in the mountains" since dropping the subject-predicate combo "they liked" creates a gerund phrase similar to the other elements.  Look out for parallel structure since many SAT questions involve this structural fault.