Everybody knows what a comma is. It’s a punctuation mark that indicates a pause, right? Well, yes. However, the comma has several other functions, which I explain in this post.

1: Separating items in a list

Without commas, lists would be a shambolic mess. For example, “My fridge contains milk butter apples oranges and tomatoes.” Yikes! Add commas, though, and a list becomes more readable: “My fridge contains milk, butter, apples, oranges and tomatoes.” Much better.

I’m sure I’m not telling you anything you don’t already know. However, you need only search the Internet to find some spectacular fails. Check this one out courtesy of writing.com:

The Oxford comma

Many writers, particularly in academia, use a comma between the last two elements of a sentence. Others, me included, don’t usually bother. However, there are situations where an Oxford comma, as it’s known, is necessary for clarity.

Here is a sentence that needs an Oxford comma: “I would like to thank my parents, Julie and God.”

Reading this sentence, you might think that the writer’s parents are Julie and God. Obviously, this isn’t the case. So, a better way to punctuate this sentence is to include the Oxford comma as follows: “I would like to thank my parents, Julie, and God.”

Fun fact: An Italian printer named Aldus Manutius can take credit for the comma as we know it today. In the late 1400s, a slash mark (/) indicated a pause in speech. For reasons known only to him, Manutius decided to make the slash lower and curved slightly. By the 1950s, the new mark became known as the Greek name comma, which literally means “a piece cut off.”

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2: Before coordinating conjunctions

Use a comma before for, and, nor, but, or yet and so (remember FANBOYS) to separate two independent clauses.

Here are some examples:

  • I hate using plastic, for it’s harmful to the environment.
  • Jane likes to ride her bike, and Tony prefers to drive his car.
  • Jack won’t eat broccoli, nor will he touch spinach.
  • I love writing, but I can only get motivated first thing in the morning.
  • You can go for a run, or you can take the car.
  • Joe is fascinated by cars, yet he doesn’t hold a driver’s license.
  • Tom hates socialising, so he never goes to the pub.

Note that an independent clause contains a subject and a verb.

What about because?

The word because is not a coordinating conjunction, so when using it to separate two independent clauses, a comma isn’t needed.

3: Addressing someone directly

When you address someone directly, you should offset their name with a comma. Here’s what I mean:

  • “What’s the time, Jim?”
  • “Jim, what’s the time?”

Using a comma in this situation may seem a little unnecessary, but, again, it’s often necessary to avoid confusion.

Check this out:

4: Separating introductory elements

Use a comma to separate the opening part of a sentence  

Here are some examples:

  • At the crack of dawn, John dragged himself out of bed to get ready for work.
  • Given his fear of heights, it is surprising that Mike took up skydiving.

If the introductory element is short, it’s usually okay to leave out a comma.

 For example:

  • After a powernap I felt like a million dollars.
  • Soon we’ll be heading into town.

Sometimes, though, a short introductory element needs a comma to improve the readability of a sentence.

For example:

  • Outside the garden resembled a jungle.
  • Outside, the garden resembled a jungle (better)

5: Separating parenthetical elements

Parenthetical, now, that’s a flash word! Basically, a parenthetical element is additional information that isn’t essential to the sentence.

Here’s an example:

  • Tony’s wife, Mary, loves roller skating.

Why is Mary not essential to the sentence? Well, unless Tony has several wives, knowing that his wife’s name is Mary isn’t important for clarity.

However, if Tony is married to Mary, Jenny and Tracey (lucky guy), then knowing which wife loves roller skating is necessary.

So, if Tony lives in a polygamous relationship, the sentence should read as follows:

  • Tony’s wife Mary loves roller skating.

You can separate parenthetical elements in other ways also, such as

  • Tony’s wife (Mary) loves roller skating.
  • Tony’s wife — Mary — loves roller skating.

Try out this comma quiz

If you find commas to be confusing, I hope this post has been of help. To see if you’re now on the right track, have a go at this quiz. Good luck!


Well, done. You have passed the comma quiz!

Not bad. Give the quiz another try.

#1. Who is credited for inventing the comma?

#2. Which sentence is incorrect?

#3. Which sentence needs a comma?

#4. Which sentence is incorrect?

#5. Which sentence is correct?

#6. Which sentence needs an Oxford comma?

#7. Which is not a coordinating conjunction?

#8. Which introductory element is missing a comma?


  1. Andrew,
    I loved your example of let’s eat Jane. That one really points out the need of a comma. Thanks for the tips and examples here. They are very helpful. Who would imagine a little comma can be a big difference?

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