“If you cook Elmer will do the dishes.”


As you can see from the sentence in the headline, which appears in Hacker and Sommers’s Rules for Writers (7th edition), a missing comma can make for some pretty funny reading—even if we didn’t intend to be amusing.

For some people, though, commas are no laughing matter. Not long ago a friend of mine cried as she told me her tale of comma woe (which involved a mean-spirited professor, a red pen, and a classroom full of laughing students).

The rules regarding comma use are finite and are not too difficult to learn, though. Below are a few rules you might find especially helpful:


Use a comma between all items in a series (known as the Oxford, or serial, comma). Although some argue that a comma before the last item in a series is not necessary or, as might be the opinion of a newspaper editor, takes up too much space, I use it because it makes clear what otherwise might be confusing.

  • CORRECT: I love my parents, Lady Gaga, and Humpty Dumpty (from Grammarly).
  • UH-UH: I love my parents, Lady Gaga and Humpty Dumpty.


Use a comma before a coordinating conjunction (think FANBOYS—for, and, nor, but, or, yet, so) ONLY when what follows that conjunction is a complete sentence with a subject and a verb (an independent clause).

  • CORRECT: I will cook Elmer, and I will also do the dishes.
  • UH-UH: I will cook Elmer, and will also do the dishes.


Use a comma after an introductory clause or phrase.

  • CORRECT: After taking a very long bus and train ride, my cousin said she was tired and wanted to go to bed.
  • UH-UH: When Irwin was ready to iron his cat tripped on the cord (from Rules for Writers, 7th edition).
  • EXCEPTION: You can omit the comma if the clause or phrase is short and the sentence will not be confusing without it. (Example—For once she was happy to see him.)


So now you know.


Is “I slept I ate.” a run-on sentence? Find out.

Sometimes when, after kissing me, she opened the door to go, I longed to call her back, to say to her ‘Kiss me just once again,’ but I knew that then she would at once look displeased, for the concession which she made to my wretchedness and agitation in coming up to me with this kiss of peace always annoyed my father, who thought such ceremonies absurd, and she would have liked to try to induce me to outgrow the need, the custom of having her there at all, which was a very different thing from letting the custom grow up of my asking her for an additional kiss when she was already crossing the threshold.” 

∼ from Swann’s Way by Marcel Proust

When asked to define a run-on sentence, people will often say it is an overly long sentence. Actually, though, the error has little to do with sentence length, since the sentence “I slept I ate.” consists of just 4 words and is, in fact, a run-on sentence, while the sentence quoted above is 116 words long and is grammatically correct.

Interesting! Yes?

From the first volume of Proust’s seven-volume novel In Search of Lost Time (also translated as Remembrance of Things Past), considered by many to be one of the greatest works of literature ever written, this 116-word sentence is entirely grammatical, but, because it contains a number of dependent clauses, it is difficult to follow and requires focus and determination when we read it.

On the other hand, “I slept I ate.” is a fused sentence—a type of run-on sentence—because it lacks internal punctuation and instead “fuses” together two complete sentences (or independent clauses, with a subject and verb, that can stand alone).

One type of run-on sentence, then, is a fused sentence; the other type is a comma splice, or two or more independent clauses that are separated (or “spliced”) by a comma. A comma splice is a very common error, as in this example: I went home for dinner, I finished my report. In English, it is never correct to separate two independent clauses with a comma.

To fix a run-on sentence (either a fused sentence or a comma splice), do this:

  • INCORRECT (fused sentence) I slept I ate.
  • CORRECT (three possible fixes) • I slept. I ate. • I slept; I ate. • I slept, and I ate.
  • INCORRECT (comma splice) I went home for dinner, I finished my report.
  • CORRECT (three possible fixes) • I went home for dinner. I finished my report. • I went home for dinner; I finished my report. • I went home for dinner, and I finished my report.

So now you know.

Here’s the lowdown on the colon:


Recently I wrote about our much-misused friend, the semicolon; now that you’ve mastered the art of using the semicolon correctly, I thought I’d spend a little time talking about another misunderstood punctuation mark: the colon.

Here are several commonly known uses: 1) following a salutation in a formal letter or email (Dear Dr. Jones:); 2) in delineating hours and minutes (4:15); 3) when separating a book’s title and subtitle (The Wild West: A Study in Contrasts); 4) when indicating proportions (The ratio of cats to dogs was 4:1.); and 5) in writing bibliographic citations (New York: HarperCollins, 2008).

Perhaps less known or understood is its use in the following instance: after an independent clause (a sentence with a subject and verb that can stand alone). In this case, you would use a colon when you want to direct your reader’s attention to 1) a list, 2) a quotation, 3) an explanation or a summary, or 4) an appositive (a noun or noun phrase that sits right next to another noun and renames it or describes it in another way). Here are some examples:

  • My morning ritual includes the following: yoga, a shower, a good breakfast, and meditation. (a list)
  • Think about these wise words from Ben Franklin: “There never was a good war or a bad peace.” (a quotation)
  • Happiness is like hope: It cannot be forced. (an explanation or a summary)
  • My dog is guilty of two of the seven deadly sins: sloth and gluttony. (an appositive)

Here are the most common misuses of a colon:

  • After a verb (The best things you can do to lose weight are: control portion sizes and get plenty of exercise.)
  • After a preposition (The book consists of: nine chapters and an afterword.)
  • After for example, such as, and including (The recipe has just a handful of ingredients, including: flour, eggs, and vanilla.)

So now you know.