There are many ways to botch the logical organization of a sentence. Here are examples of five variations, along with discussion and revision of each.
1. You can help not only position your organization for success when audited, but you can focus on protecting the sensitive information of your patients.
Probably the the most common of problems with parallel structure is the mangling of “not only . . . but also” comparisons. When a verb sets up both the “not only” point and the “but also” counterpoint, it must precede “not only” so that it is not bound up with the first point and the “but also” phrase can therefore share it. Conversely, when each phrase contains its own verb, as here, one verb must follow “not only” and the other verb must follow “but also”: “You can not only help position your organization for success when audited, but you can also focus on protecting the sensitive information of your patients.”
2. She is as foolish, if not more foolish than, her fans.
When a parenthetical phrase appears in a sentence, be sure that the sentence remains grammatically valid without it. When the interjection “if not more foolish than” is omitted from this sentence, what remains “She is as foolish her fans.” Because that sentence requires a second as to be inserted, after foolish, it belongs there when the parenthetical is included as well: “She is as foolish as, if not more foolish than, her fans.”
3. Employers can better communicate with this rapidly growing generation to increase their interest and retention of health, safety and loss-prevention training.
Another common error in parallel structure is to assume that two nouns can share a preposition, when each requires its own. Here, “retention of” is a correct prepositional phrase, but interest does not combine with of; it requires its own idiomatic partner: “Employers can better communicate with this rapidly growing generation to increase their interest in and retention of health and safety loss-prevention training.” (The second prepositional phrase, bundled with and, can be parenthesized with commas, but the punctuation is not necessary.)
4. They called him sexist, racist, and highlighted his contentious relationship with the industry.
This sentence makes three points: The person is sexist, the person is racist, and the person has a contentious relationship with the industry; observers are said to have labeled him with the first two negative qualities and emphasized a third factor. Just as the statement preceding the sentence you are reading right now has three verbs in the first clause, the original sentence requires a verb for each point. Better yet, the first two can be joined with a conjunction, rather than divided by a comma, so that they can share called: “They called him sexist and racist and highlighted his contentious relationship with the industry.”
5. Enforcement actions by regulators in the United Kingdom are usually less severe in comparison to the United States.
Sometimes, the absence of a word or phrase renders a comparison incomplete. Here, enforcement actions are being faultily compared to a nation. For enforcement actions in one nation to be compared to enforcement actions in another nation, the detail, or a paraphrase of it (in this case, “those of”) must be reiterated: “Enforcement actions by regulators in the United Kingdom are usually less severe in comparison to those in the United States.”