For such a common punctuation mark, the comma is certainly complicated. But it’s worth learning to use commas correctly. After all, anything important you write will be full of them!

To mark Punctuation Day 2022, let’s look at five of the top comma-related issues to avoid so that you can make your work as polished and reader-friendly as possible.

1. Believing that commas don't really matter

There’s more to life than commas, but they are important! Using punctuation accurately and thoughtfully improves the clarity and flow of your writing and this, in turn, is an act of empathy towards your readers. Whoever they are, you can assume they’re busy and want to be able to understand your ideas quickly and easily.

Consider these two sentences, for example, and the confusion you could create without the correct commas:

The student said the tutor has an impressive grasp of punctuation.

The student, said the tutor, has an impressive grasp of punctuation.

Taking care over your punctuation is, of course, in your own interests as well. It shows your reader that you’re a conscientious, capable writer. And when that reader is a tutor, examiner or potential employer, it’s worth doing all you can to make a good impression!

So, with that in mind, let’s look at some of the most frequent problems that arise with commas and how to fix them.

2. Using a comma splice

A 'comma splice' is the incorrect use of a comma to join two independent clauses (two clauses that could both stand alone as separate sentences).

The text was poorly punctuated, I found it distracting.

This little comma might seem harmless enough, but it’s sure to bother anyone who feels strongly about punctuation – and that includes many tutors and recruiters.

You might see commas used this way in poetry and novels, but then creative writing can, as its name implies, be more creative with punctuation. If you're writing an academic essay or a job application, the rule is simple: avoid the comma splice!

How to fix it

Here are three ways to join independent clauses correctly:

  • Use a full stop.

The text was poorly punctuated. I found it distracting.

  • Use a semicolon.

The text was poorly punctuated; I found it distracting.

  • Add a conjunction like 'and' or 'but'.

The text was poorly punctuated and I found it distracting.

3. Forgetting the second comma in a pair

‘Bracketing commas’, also known as ‘isolating commas’, are used to mark off an interruption from the main clause of a sentence. (For an example, see my last sentence.)

When an interruption comes in the middle of a sentence, as this one does, it's usually helpful (and often necessary) to set it off with commas. And if you use one comma, don’t forget the second one!

Notice how a sentence becomes slightly more confusing when the second comma is missing:

Commas, it would seem can help readers process a sentence more easily. [incorrect]

Commas, it would seem, can help readers process a sentence more easily. [correct]

How to fix it

As you write a sentence, ask yourself these questions:

  • What’s the main clause in this sentence?
  • Is there an interruption from this main clause?
  • Do I need to set this interruption off with a pair of bracketing commas?

The main clause should make sense on its own, even with any interruptions removed.

Now consider where you'd add commas in this sentence:

Commas like brackets or dashes can be used to set off an interruption from the main clause of a sentence.

4. Putting a comma between a main verb and its subject

Take a look at the sentence below. Where's the main verb and what is its subject? How easy is this sentence to read?

A frequent problem that readers experience and that can stand in the way of their being able to make sense of a sentence easily, is that the sentence begins with a very long subject.

As you probably noticed, the main verb (‘is’) comes late in the sentence and the subject (‘A frequent problem […] easily’) is very long. The sentence sounds awkward and it's pretty hard work to read.

It’s tempting to think that adding a comma will help the reader see where the subject (finally) ends – and, in fairness, it does. But it also messes up the grammar of the sentence. We’d never write ‘The cat, sat on the mat’.

How to fix it

The simple answer is to delete the comma, but this doesn’t solve the original problem. A better solution? Restructure or simplify the sentence to get rid of the long subject at the beginning:

Sentences can be difficult to process when they begin with very long subjects.

Your reader will thank you!

5. Forgetting the comma before a non-essential clause

Should you use a comma before a ‘who’ or ‘which’ clause? Well, it depends. Let’s look at an example:

Bath is a city which has long attracted large numbers of visitors.

In this sentence, ‘Bath is a city’ isn't much use on its own. It's the bit after 'which' that we're interested in. Here, it would be wrong to add a comma because the ‘which’ clause is integral to the sentence.

Now consider this example:

Bath is famous for its Georgian buildings, which are constructed from golden-coloured stone.

Here, the first part of the sentence (‘Bath is famous for its Georgian buildings’) is already informative on its own. The ‘which’ clause is simply providing extra information about the Georgian buildings. Before this kind of add-on clause, we do need a comma.

How to fix it

A quick tip is to ask yourself this question:

Is the information in the relative clause (after ‘which’, ‘who’, etc.) essential to the sentence?

Yes? Don't use a comma.

No? Use a comma.

If you're still in doubt, read the sentence aloud. You can usually hear the comma (or lack of comma) in these types of sentences.

So before you submit your next essay or click ‘send’ on that job application, take a few minutes to check your commas. They may seem like small details, but they can make a big difference!

If you'd like to improve your English language skills for your studies and future career, the Skills Centre runs a General English course for all students and staff who use English as a second language. On the course you'll develop your grammar and vocabulary as well as your writing, reading, listening, and speaking skills.

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