Previous posts on this website have discussed syntactical errors that result in a lack of grammatical balance between equivalent words and phrases; this post lists the various types of mistakes that lead to flawed parallel structure. You are invited to fix each sentence before reading the explanation.
Absence of One Word
Most sentences with faulty parallel structure merely lack one word that, once added, repairs the damaged equivalence. The multiple examples in this section illustrate an array of problematic sentence constructions.
1. More diverse corporate leadership will lead to better decision-making and products and services that are more relevant to customers.
The adjective better refers only to decision-making, not to products and services, which share a distinct phrase that, like better, qualifies a benefit; inserting to before those terms to match the preposition preceding “better decision-making” clarifies that the sentence has a compound predicate: “More diverse corporate leadership will lead to better decision-making and to products and services that are more relevant to customers.”
This problem also occurs in sentences that feature an in-line list (a succession of equivalent words or phrases, set off by identical punctuation marks, that appear within the horizontal structure of a sentence rather than being formatted vertically, like items on a shopping list).
Often, a compound predicate is mistaken for an in-line list, which requires insertion of a supporting conjunction and deletion of an intrusive punctuation mark.
2. Crowds fled in panic, taking shelter in shops, hotels, or leaping off the elevated pavement onto the beach below.
This sentence is formatted as a list, implying that people employed one of three methods to escape danger—resorting to shops, hotels, or the beach. However, only two survival strategies were employed: taking shelter in one of two types of business establishments, or leaping onto the beach. The sentence, therefore, must be slightly revised to refer collectively to shops and hotels as two examples of the implied category “structures in which to seek refuge”: “Crowds fled in panic, taking shelter in shops or hotels or leaping off the elevated pavement onto the beach below.”
3. The contraception app has become a popular alternative because it doesn’t involve taking any medicines, inserting devices, or hormone patches.
Here, the three alternative contraception methods must be treated with the same structural support—because verbs accompany medicines and devices, “hormone patches” requires equivalent treatment: “The contraception app has become a popular alternative because it doesn’t involve taking any medicines, inserting devices, or using hormone patches.”
4. Those complaints ranged from water dripping from ceilings and walls, gas leaks, electrical shorts, and stopped-up toilet bowls—or no toilet bowls at all.
Often, a “from . . . to” construction is flawed because in the assembly, to has been omitted, but it is required to complete the equivalence: “Those complaints ranged from water dripping from ceilings and walls to gas leaks, electrical shorts, and stopped-up toilet bowls—or no toilet bowls at all.” (Note that no punctuation interrupts the from . . . to continuum; this is true even if to is employed more than once.) Better yet, however, when the order of words or phrases in the list does not obviously express an ascending significance, employ a simple list structure that omits from and to: “Those complaints included water dripping from ceilings and walls, gas leaks, electrical shorts, and stopped-up toilet bowls—or no toilet bowls at all.”
Incorrect Word Order
The sequence of words, rather than an absence of words, can impede logical syntax.
5. Employers frequently have resource needs, both as part of digital-transformation initiatives and other projects.
“As part of” applies only to “digital-transformation initiatives,” not to the corresponding phrase “other projects,” so “as part of” must be repeated before the latter phrase: “Employers frequently have resource needs, both as part of digital-transformation initiatives and as part of other projects.” Better yet, simply transpose both and “as part of” so that the phrase applies to both corresponding phrases: “Employers frequently have resource needs, as part of both digital-transformation initiatives and other projects.”
Absence of One Word and Incorrect Word Order
Sometimes, a sentence is flawed in both respects.
6. The cynic in me believes it’s rarely done for aesthetic reasons but for strictly commercial ones.
This sentence requires a counterpoint to rarely, and because that adverb and its opposite must share the verb done, the verb must precede both adverbs: “The cynic in me believes it’s done rarely for aesthetic reasons but often for strictly commercial ones.”
Insertion of Extraneous Word
Here, a superfluous repetition of a preposition disrupts a sentence’s parallel structure.
7. These processes can be used to evaluate internal controls to prevent and detect drug diversion in inpatient and outpatient pharmacies, research facilities, and in clinical and procedural areas.
Repeating the preposition in before each example of a place where drug diversion can occur is a valid (but unnecessary) alternative to allowing a single iteration to support the entire list, but this sentence is flawed in that it does not succeed in applying either choice—either “research facilities” must be preceded by in, or, as shown here, the instance of the preposition before the final list item can be omitted: “These processes can be used to evaluate internal controls to prevent and detect drug diversion in inpatient and outpatient pharmacies, research facilities, and clinical and procedural areas.”
Incorrect Inflectional Form
Occasionally, the error is the wrong inflectional form of a word, rather than omission of a necessary word or insertion of an extraneous one.
8. It has chosen to reach settlements rather than levying civil monetary penalties in all but the rarest of cases.
Here, to match the bare inflectional form reach, levying must be pared down to levy: “It has chosen to reach settlements rather than levy civil monetary penalties in all but the rarest of cases.”
Misuse of “As Well As”
The phrase “as well as” is often misunderstood to be a conjunction.
9. This type of assessment helps further inform management’s overall risk tolerance, target fit, valuation assessments, as well as the overall strength of the target.
“As well as” is not equivalent to and or or, so when the last item of an in-line list is preceded by that phrase, rephrase the sentence so that “as well as” and what follows constitute a clause separate from the list (and insert a conjunction before what is now the final list item): “This type of assessment helps further inform management’s overall risk tolerance, target fit, and valuation assessments, as well as aiding in measuring the overall strength of the target.” Alternatively, do so but replace “as well as” with an additional conjunction (“This type of assessment helps further inform management’s overall risk tolerance, target fit, and valuation assessments and aids in measuring the overall strength of the target”) or incorporate the clause into the list (“This type of assessment helps further inform management’s overall risk tolerance, target fit, valuation assessments, and measure of the target’s overall strength”).