A run-in list is one that is incorporated into the body of a sentence, rather than formatted as a numbered, unnumbered, or bulleted list with each item on a separate line. Such a list, unfortunately, often invites errors when writers don’t attend to interrelationships among the items or become intimidated into believing that organizing the items is more complicated than it really is. Here are three types of errors introduced into run-in lists and how to remedy them.
1. “Students plant trees to halt coastal erosion, monitor water quality, and educate others about the importance of environmental stewardship.”
As written, the sentence suggests that students plant trees to accomplish the three goals subsequently listed. However, the trees were planted only to control coastal erosion; the other two items in the sentence are separate activities.
To eliminate ambiguity, reorder the three items, simultaneously improving the sentence rhythm by placing the activity descriptions in order according to the length of the phrase: “Students monitor water quality, plant trees to halt coastal erosion, and educate others about the importance of environmental stewardship.”
2. “With severe fetal alcohol syndrome, there can also be organ deformities, including heart defects; heart murmurs; genital malformations; kidney and urinary defects.”
Semicolons are necessary in a sentence containing a run-in list only if one or more items in the list are themselves lists and the sentence cannot be reorganized otherwise. In this case, the list is not complex — it consists of a simple roster of typical organ deformities — and semicolons are not required.
Also, the conjunction in “kidney and urinary defects” does not serve as a final conjunction in the list unless “kidney defects” and “urinary defects” are treated as distinct list items separated by a comma and the conjunction; because they are combined into one item, they must be preceded, as is, by a conjunction.
However, to improve sentence rhythm, I placed “genital malformations” as the last item, so the conjunction precedes that phrase: “With severe fetal alcohol syndrome, there can also be organ deformities, including heart murmurs and other conditions, kidney and urinary defects, and genital malformations.”
3. “Preliminary research shows that it: reduces the risk of trauma, decreases the frequency and severity of alcohol misuse, and increases enrollment in specialized alcohol abuse treatment.”
A colon should precede a list only when what precedes the colon is a full clause. In this case, the preceding wording is a simple phrase; the colon between the pronoun and the verb is a clumsy interruption: “Preliminary research shows that it reduces the risk of trauma, decreases the frequency and severity of alcohol misuse, and increases enrollment in specialized alcohol abuse treatment.”
(A colon is appropriate in this revision, which is wordier than necessary: “Preliminary research shows that it has the following outcomes: It reduces the risk of trauma, decreases the frequency and severity of alcohol misuse, and increases enrollment in specialized alcohol abuse treatment.”)
On the second example: Heart murmurs are not necessarily deformities; I assume they could be called a functional imbalance (as in function vs. stucture). However, genital malformations are. The way the sentence is originally written confuses the separate categories of conditions, and the re-write fails to correct this. I would edit the sentence as follows:
“Severe fetal alcohol syndrome can cause kidney and urinary defects, heart murmurs, and organ deformities, such as genital malformations and heart defects.”
My subsidiary point is that sometimes it may be helpful to know the intricacies of the subject of the writing one is editing.