In each of the following sentences, the absence of inadvertently omitted words and phrases leads to sentences that, though comprehensible, do not really say what they set out to communicate. Discussion after each example explains the problem, and revisions offer solutions.
1. The Voice mentor and Maroon 5 front man seemed to phone it in early on during the concert.
In this sentence, the writer is under the mistaken impression that an article that is part of a composition title can serve double duty as an article integral to the syntax of the sentence in which the title is located. Replace the title with any other phrase that does not begin with the to see the problem. In this case, because the person in question is identified with phrases referencing two entertainment enterprises in which he is involved, simply insert an article at the head of the sentence and transpose the two phrases: “The Maroon 5 front man and The Voice mentor seemed to phone it in early on during the concert.”
When this solution is not available because only one identifying phrase is employed, recast the sentence otherwise: “Levine, one of the mentors on The Voice, seemed to phone it in early on during the concert.” This revision is not as concise, but it has the advantage that it, unlike the original version, is syntactically sound.
2. We have observed systems at sites that often do not require any user authentication to interact with the physical environment and utilize unsupported and unpatched system software.
It is initially unclear to the reader whether the phrase “utilize unsupported and unpatched system software” is parallel with the phrase “interact with the physical environment” or with the larger phrase that begins with require and ends with environment. Because the latter choice is the correct one, that should be repeated before the phrase beginning with utilize to match that phrase with the one beginning with require: “We have observed systems at sites that often do not require any user authentication to interact with the physical environment and that utilize unsupported and unpatched system software.”
3. Mobile app usage rates are flat but are now higher than ATMs.
Here, mobile app usage rates are erroneously compared with ATMs; the comparison is between mobile app usage rates and ATM usage rates, and the sentence should explicitly state this, if only with a pronoun phrase in place of specifically parallel wording: “Mobile app usage rates are flat but are now higher than those for ATMs.”