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Tag: Lists

  • How to Use Semicolons in a List (When Commas Alone Won’t Work)

    If a list of things already has commas inside each item, plain commas between the items stop working — the reader can’t tell where one item ends and the next begins. The fix is to swap the commas between items for semicolons instead. Think of a semicolon here as just a bigger comma: same job, does it more visibly.

    The rule you can actually repeat

    Here’s the one-liner: if any item in your list already contains a comma, upgrade every comma between the items to a semicolon. That’s it. You’re not adding punctuation for style — you’re removing an ambiguity that was already there.

    This comes up constantly in academic writing, because academic lists are rarely single words. They’re names with titles, places with countries, results with their own numbers attached — and every one of those has an internal comma waiting to collide with the commas holding the list together.

    The classic case: a list of people with titles

    Say you’re listing your thesis committee. Written with commas only, it reads like this:

    We had four professors on our committee: Peter Wursthorn, Professor of Mathematics, Ronald Pepin, Professor of English, Cynthia Greenblatt, Professor of Education, and Nada Light, Professor of Nursing.

    Count the commas and you’ll see the problem — there’s no visual difference between “the comma that separates a name from a title” and “the comma that separates one person from the next.” A reader seeing this cold could plausibly parse “Ronald Pepin” and “Professor of English” as two separate committee members. Semicolons fix it instantly:

    We had four professors on our committee: Peter Wursthorn, Professor of Mathematics; Ronald Pepin, Professor of English; Cynthia Greenblatt, Professor of Education; and Nada Light, Professor of Nursing.

    Now the semicolons mark the real boundaries, and the commas are free to do their smaller job inside each item.

    The version that shows up in methods sections

    The same collision happens with data, and it’s an even easier one to miss because the numbers look fine on their own:

    The participants in the first group scored 70 points, the second, 60, and the third, 40.

    Read that sentence at normal speed and you’ll stumble somewhere around “the second, 60.” Semicolons make the three results sit apart cleanly:

    The participants in the first group scored 70 points; the second, 60; and the third, 40.

    And you’ll see this same pattern anywhere you list sample sites or affiliations — “Kaohsiung, Taiwan, Osaka, Japan, and Busan, South Korea” is exactly the same problem in disguise, because “Taiwan” and “Osaka” now sit next to each other with nothing marking the join. Semicolons after each country name solve it the same way: “Kaohsiung, Taiwan; Osaka, Japan; and Busan, South Korea.”

    Where it still catches people out

    The rule is simple, but people misapply it in the opposite direction too — sprinkling semicolons into a plain list that never needed them, because “semicolons sound more academic.” They don’t. A list of single words or short phrases (“apples, pears, and bananas”) never needs a semicolon, no matter how formal the paper is. The semicolon only earns its place once a comma is already doing a smaller job inside one of the items. If nothing in the list has an internal comma, leave it alone.

    If it’s easier to see this in motion than read it, University English Hub has a short video walking through the same two examples — worth two minutes if you want the rule to stick before your next revision pass.

    This is one of the original Uni-edit writing tips — if punctuation like this is the kind of thing you’d rather a second pair of eyes just caught, it’s exactly what Level 3 editing is built to fix, alongside grammar and basic phrasing, before the sentence-level stuff ever gets in front of a reviewer.

    And if you want the next one of these before it turns into a habit you have to unlearn, Uni-edit’s writing-tips list sends them out one at a time — get our writing and publication emails here.

    A course on this, if enough people want one

    Tips like this one are the raw material for Academic Writing Essentials, a short course we are thinking about building. It does not exist yet. If it would be useful, add your name and tell us what it should cover.

    We will email you once, when it opens. Nothing else.

    Join the waitlist

  • What Is Parallel Structure? The One-Line Test for Lists and Comparisons

    Parallel structure means every item in a list, and every side of a comparison, is built from the same grammatical part: noun with noun, verb with verb, phrase with phrase. Break that match and a sentence doesn’t usually become wrong exactly — it just goes lopsided, and a reader feels the wobble before they can say why.

    Here’s the classic broken version: “problems for both the winners and for those who lose.” One side is a noun (“the winners”), the other is a clause (“those who lose”). Match the parts and it snaps into place: “problems for both winners and losers.” Same meaning, half the effort to read.

    The one-line test: read it as a list

    Here’s the rule you can actually repeat to a labmate: find the shared stem, then check that every branch off it is the same part of speech. Take this sentence:

    Wrong: “Mike learned to read poems critically and he appreciated good prose.”

    The stem is “Mike learned to…” Plug in the first branch and it works: “Mike learned to read poems critically.” Plug in the second branch and it doesn’t — “Mike learned to he appreciated good prose” is nonsense, because the second half quietly switched from an infinitive to a full clause. Fix it by making both branches infinitives:

    Right: “Mike learned to read poems critically and to appreciate good prose.”

    That’s the whole test. You don’t need to name the parts of speech out loud — you just need to notice when plugging a branch back into the stem stops sounding like a sentence.

    Where it hides in an aims sentence

    This is the version we see constantly in the last line of an introduction, where a paper states its objectives:

    Wrong: “The aim of this study was to characterize the mutation and evaluating its downstream effects.”

    Run the test: the stem is “The aim … was to…” — “to characterize the mutation” plugs in fine, “to evaluating its downstream effects” doesn’t, because it drifted from infinitive to gerund halfway through. One word fixes it:

    Right: “The aim of this study was to characterize the mutation and evaluate its downstream effects.”

    It’s an easy slip to make, because both halves sound fine read alone — the mismatch only shows up once you say them against the shared “to.”

    The version that hides in a comparison

    Parallelism isn’t only about lists joined by “and” — it governs comparisons too, and this one is sneakier because the sentence still parses, it just compares two different kinds of thing:

    Wrong: “Our results were more consistent than the control group.”

    Read literally, that compares “our results” to “the control group” — a set of numbers against a group of people. What the writer means is a comparison between two sets of results:

    Right: “Our results were more consistent than those of the control group.”

    “Those of” is doing real work there — it’s what keeps both sides of “than” the same kind of thing. Reviewers rarely flag this explicitly, but it’s exactly the sort of line that makes a paragraph feel slightly harder to trust than it should, even when every fact in it is solid.

    Why it’s worth catching before submission

    None of these errors change what the data show. What they change is how much work a reader has to do to get there — and a reviewer who’s re-reading your aims sentence to figure out what you meant is a reviewer who’s no longer thinking about your results. Parallel structure is one of those things that costs nothing to fix and quietly buys back a reviewer’s patience.

    The original Writing Tip 3 on the main site continues into the trickier cases this post didn’t have room for — repeating “the” correctly across a list, and getting “both…and” and “not only…but also” to line up — if you want the fuller reference.

    If this is the kind of sentence-level snag you’d rather someone else caught before a journal sees it, that’s the level our editing service works at — line by line, alongside grammar, phrasing and structure generally.

    And if you’d rather have one of these land in your inbox before it lands in your draft, our writing and publication emails send out one point like this at a time.

    A course on this, if enough people want one

    Tips like this one are the raw material for Academic Writing Essentials, a short course we are thinking about building. It does not exist yet. If it would be useful, add your name and tell us what it should cover.

    We will email you once, when it opens. Nothing else.

    Join the waitlist