Punctuation Mistakes #1: Unnecessary Commas

By Maeve Maddox

A common error with commas is to sprinkle them where they don’t belong. Here are five examples of this type of comma error.

Incorrect: The laptop on the table, is mine.
Correct: The laptop on the table is mine.

Do not separate a subject from its verb. The subject is “The laptop on the table.”

Incorrect: Motel rooms, that are dirty, ought to be illegal.
Correct: Motel rooms that are dirty ought to be illegal.

Do not set off a restrictive clause. The clause “that are dirty” is essential to the meaning of “motel rooms.” No commas are needed.

Incorrect: The dog understood at once, what his handler wanted.
Correct: The dog understood at once what his handler wanted.

Do not separate a verb from its direct object or complement. The clause “what his handler wanted” is the object of the verb understood.

Incorrect: Jethro wanted to be either a brain surgeon, or a fry cook.
Correct: Jethro wanted to be either a brain surgeon or a fry cook.

Do not use a comma to separate paired elements joined by coordinate conjunctions. The paired elements are “a brain surgeon” and “a fry cook.” No comma is needed.

Incorrect: The famous author lives in a small town, because she doesn’t like the noise of a big city.
Correct: The famous author lives in a small town because she doesn’t like the noise of a big city.

Do not set off an introductory independent (main) clause from a following dependent clause. “The famous author lives in a small town” is the main clause.

Note: if the dependent clause comes first, a comma is needed: “Because she doesn’t like the noise of a big city, the famous author lives in a small town.”

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11 Responses to “Punctuation Mistakes #1: Unnecessary Commas”

  • Tomas Donoval

    It seems as if these sentences were written (or translated) by a native Slovak speaker because apart from example No. 1, all commas would just be in their right places if the text was written in Slovak.

  • SallyMJ

    I agree with these rules.

    At the same time, don’t we sometimes need to add elective commas if a sentence or clause is very long? I give the sentence the “breath” test, and put a comma where I would take a breath with long sentences.. I appreciate extra commas if the sentence is long. It helps me not lose my place. Surely I am not the only one.

  • venqax

    Just, kidding. 🙂

  • Precise Edit


  • venqax

    “When I get to the proofreading stage of the editing process, I spend a lot of times fixing comma errors…”

    Should that comma be there?

  • Precise Edit

    I put in more commas than I take out, but the ones I take out match these errors. MS Word often suggests unnecessary commas, and for too many people believe MS Word is correct.

  • Roberta B.

    bluebird – In addition to the odd placement of a comma, I’d be just as concerned that the sentence started off as “This [what?] is a……woman……” Shouldn’t it start with “The patient is a……woman…”?

  • thebluebird11

    I agree with Precise Edit. Most of my job involves editing medical reports. Most of our documents actually are created by a speech engine, and the first thing that annoys me is how they start off with “This is a 40-year-old woman, who came to the hospital…” What on earth is that comma doing there?? More commas are sprinkled throughout the reports for no apparent reason. Thank the keyboard gods for the delete key.

  • Curtis

    My experience is the opposite of that of Precise Edit: far too many sentences made confusing by the omission of needed commas.

  • Bill

    Great samples, clear explanations. Thanks!

  • Precise Edit

    Excellent! When I get to the proofreading stage of the editing process, I spend a lot of times fixing comma errors, putting them in where needed and taking them out where not needed. You have nailed the most common mistakes I find of unnecessary commas. Many people use a sort of salt shaker approach to commas, and they sprinkle them in liberally.

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