Repeating function words to clarify parallels
Function words such as prepositions and subordinating conjunctions signal the grammatical nature of the word groups to follow. Although they can sometimes be omitted, include them whenever they signal parallel structures that might otherwise be missed by readers.
In the original sentence, the prepositional phrase was too complex for easy reading. The repetition of the preposition to prevents readers from losing their way.
A second subordinating conjunction helps readers sort out the two parallel ideas: that Julie was extremely farsighted and that corrective lenses would help.
If it is possible to streamline the sentence, repetition of the function word may not be necessary.
Instead of linking two subordinate clauses beginning with that, the revision streamlines the sentence by balancing the two parts of a compound predicate—had done well in the first quarter and had since dropped in value.
Exercise: Identifying parallel structure
preposition A word placed before a noun or noun equivalent to form a phrase modifying another word in the sentence: They fell in line with the crowd.
subordinating conjunction A word that introduces a subordinate clause and indicates its relation to the rest of the sentence: although, because, while, when.
subordinate clause A word group containing a subject and a verb that cannot stand alone as a sentence because it begins with a word that marks it as subordinate (such as although, because, who, or that).
compound predicate Two verbs or verb phrases joined with a coordinating conjunction in one clause and sharing one subject.