Comma, comma, comma chameleon: why the comma is the most difficult of all punctuation marks

person typing on typewriter

I hope everybody has a friend like Sam. I’m so lucky to have had her as my first mentor when training to be an English teacher. She’s a true force of nature: unashamedly authentic, arrestingly articulate, and always challenging people’s BS - no matter which direction it’s blowing in from. She’s clever and warm and confident, and yesterday, after reading my semi-colon post, she asked for a post on commas. All this is to say that if Sam - the woman I want to be when I grow up - would like to get commas straightened out, then there is no shame in anyone wanting to clear up commas in their writing toolkit. So comma righta thissa waya (I’m so sorry) for a masterclass on the little tadpole of punctuation… 


They might seem basic, as they are so common (or even comma-n? Sigh. Apologies again.) But don’t be fooled. Using commas correctly is a little bit like boiling an egg. Oh yeah, people assume it’s easy - hence all the snobs who scoff, ‘He can’t even boil an egg!’ - but the reality is more complex. Getting the perfect set white and dippy yolk is only one step removed from rocket science, and commas are not at all easy either. Much like the skin-crawling observation of a blob of translucent gooey egg white on your soldier, an otherwise perfect piece of writing can be similarly soured when peppered with misplaced commas.

So settle down to learn about all the different jobs the versatile comma can do, and how you can get them to behave in your own sentences. When I say settle down, I really do mean it. I hope you’ve had a bathroom break! This post is a behemoth.We will look at:

  • lists

  • Oxford commas

  • parenthesis

  • dependent and independent clauses

  • tag questions

  • starting sentences

  • direct address

  • comma splicing

How to use commas in a list

Let’s start with the context that most of us can get right. You use a comma to separate items in a list, protecting your partner from a nervous breakdown at the Sainsbury’s checkout:

✘   Greg please buy apples sausages milk cheddar quiche beef tomatoes basil lemon bleach

✔︎  Greg, please buy apples, sausages, milk, cheddar, quiche, beef, tomatoes, basil, lemon, bleach

Thanks to the commas, you won’t need to skewer Greg for mistakenly buying beef tomatoes, lemon bleach, and cheddar quiche instead of the individual items.Talking of lists, let’s meet my friend, the Oxford comma…

What is an Oxford comma?

An Oxford comma divides the final two items in a list, sitting sedately before the ‘and’.

(OC)  I love to sing, dance, and act.

(No OC)  I love to sing, dance and act.

Essentially, using or spurning the Oxford comma is a matter of style (although, so is wearing socks with sandals, and there is clearly a ‘right’ side of that debate). Pedants argue over whether the Oxford comma is necessary, and I’m here to tell you now that I don’t care what anybody says, as long as you keep your writing tidy. Personally, I find it neat and orderly, as it maintains consistency in lists. It paces things nicely. It can also be very helpful in clarifying meaning.

A) Her breakfast included a banana, some yoghurt, a cup of coffee, and a slice of toast.

B) Her breakfast included a banana, some yoghurt, a cup of coffee and a slice of toast.

The second option without the Oxford comma isn’t wrong, and some publications and style guides even prefer it, but to me it seems like the ‘cup of coffee and a slice of toast’ are being gasped out in a desperate rush to finish the sentence.

That feeling of rushing is really just a style preference. However, meaning can also be eroded when you omit the Oxford comma. One such example is the famous joke about the panda, used by Lynne Truss in her well-known grammatical guide. (A panda walks into a bar, finishes a huge meal, then peppers the bar with bullets. The bemused bartender looks in the dictionary under ‘P’ and reads the definition of a panda: eats shoots and leaves).

My general advice is to use the Oxford comma, unless it seems cumbersome or strange to do so. In a very short sentence (‘I awoke, yawned and stretched’) it might seem too much to divide it up (‘I awoke, yawned, and stretched’). What do you think? It’s just a matter of taste.

How to use commas for parenthesis

I know: parenthesis is a hell of a word. Don’t try saying it after a few beers (mainly because you’ll be ejected from the party for being such a grammar bore).

Some people only think of parenthesis as brackets, especially in American English, but it can also include dashes and commas. The root of the word actually has nothing to do with parents, but it can be a helpful mnemonic anyway. Think of two parents keeping a child under their roof, and two commas keeping an idea squirrelled away between them.Parenthesis is bonus information. It adds a little extra, like colourful paint on the walls, but it’s not essential to the meaning of the sentence - or the structural integrity of the building.

Look at my sentence from a moment ago:

Some people only think of parenthesis as brackets, especially in American English, but it can also include dashes and commas.

 Some people only think of parenthesis as brackets, but it can also include dashes and commas.

The bit about American English isn’t essential, so it’s corralled in commas as a little ‘aside'. The second version, without the comma-enclosed extra, still makes grammatical and semantic sense.

Parenthetical insertions are often used to qualify, emphasise, emote and explain. You can see from a quick glance at my writing that I’m quite a fan of parenthesis, and it’s a sure-fire sign of a smart arse who always has something else to say. :)

Using a comma before ‘and’, ‘but’, and other connectives

Look, I’m not going to lie to you: trying to explain this part makes me want to shoot my own face off, so I don’t hold out much hope for your enjoyment. However, let’s both promise to do our best and then never speak of this again, OK?

When you want to join two independent clauses, you need a comma and a connective (or a semi-colon, but that’s another blog post). Let’s get to grips with that lingo. A connective (or a conjunction) is a joining word such as ‘and’, ‘but’, ‘or’, ‘yet’ and ‘so’.An independent clause is not a financially secure Santa (ho ho ho!); it’s another grammatical label. Surprise!! Who’d have thought it? If some words work together to express an idea or event, and they don’t need any extra help with this, then you can call that group of words an independent clause.

I’m just imagining things

Dev went to the party

Vanilla is the best ice cream flavour

The sun is finally outIt seemed fun

It’s no good arguing

Those babies are all independent clauses, because they can stand on their own two feet. The opposite, naturally, is called a dependent clause. A dependent clause can only work when it’s being propped up by an independent clause. Look at them trying to stand alone - it’s embarrassing, frankly:

with aliens

after a terrible morning

because of the clowns

while the music played

that was round the cornerto play

They don’t make sense alone. Given their inability to exist without an independent clause, the last thing you should do is put a comma in between the two, driving them further apart. Dependent clauses, like toddlers, have to be kept close at hand to ensure they aren’t drawing on the walls and shaving the dog.

✔︎  I’m just imagining things because of the clowns.

✔︎  Dev went to the party that was round the corner.

✔︎  The sun is finally out to play.

✔︎  It seemed fun while the music played.

✔︎  It’s no good arguing with aliens.

✘  I’m just imagining things, because of the clowns.

✘  Dev went to the party, that was round the corner.

✘  The sun is finally out, to play.

✘  It seemed fun, while the music played.

✘  It’s no good arguing, with aliens.

Can we all agree that the second set just sounds plain wrong? A pause or division in these sentences sounds stilted and unnatural.

Independent clauses, however, are grown ass adults. You can - and should - give them a bit of space. When joining independent clauses together with a coordinating connective such as ‘and’, ‘but’, ‘or’, ‘so’ and ‘yet’, you can whack a comma in there too. It’s important to remember that the connective and the comma come as a pair, here. If you only use a comma, you’re guilty of splicing (see the bottom of the post).

✔︎  Vanilla is the best ice cream flavour, so it’s no good arguing. (+ , so)

✔︎  The sun is finally out, or I’m just imagining things. (+ , or)

✔︎  Dev went to the party, and it seemed fun. (+ , and)

Look, I know that this is already mayhem, but it gets worse. I did warn you. Sometimes a word can wear more than one hat. So… I can’t tell you whether to use a comma before ‘whilst’, for example, because sometimes it’s a preposition and sometimes it’s a connective.

✔︎  I clean the car whilst singing.

‘Whilst’ is a preposition here. DEPENDENT CLAUSE: whilst singing (no comma)

✔︎  I clean the car, whilst you can never be bothered.

‘Whilst’ is a connective here. INDEPENDENT CLAUSE: you can never be bothered (comma)

✔︎  The pool is wide but shallow.

DEPENDENT CLAUSE: but shallow (no comma)

✔︎  The pool is wide, but I can swim it easily.

INDEPENDENT CLAUSE: I can swim it easily (comma)I think we should move on, don’t you? Oh, speaking of which…

Using a comma for tag questions

✔︎  It’s cold out, isn’t it?

✔︎  Monopoly is torture, don’t you think?

✔︎  You love cheese, don’t you?

✔︎  Checking out my new shoes, are you?

✔︎  I think we should move on again, shouldn’t we?

Using a comma when starting sentences

Quite often, your sentences will begin with some kind of modifier or qualifier. Yes, this is yet another situation which calls for a comma. Unfortunately, punctuation can be a real shit. Well, that’s all there is to say on this. And hey, If you’re reading carefully, you’ll see I’ve been doing it in this paragraph.

Using a comma for direct address

If you directly address a person by name, you should separate the name from the rest of the sentence with a comma.

✔︎  Fido, lie down.

✘  Fido lie down.

✔︎  You’re the greatest, Sam.

✘  You’re the greatest Sam.

(This makes it sound like she’s the largest Sam I know)

✔︎  Let’s wrap up, Mr. President.

✘  Let’s wrap up Mr. President.

(Who wants THAT as a gift? Unless we’re looking back to the Obama days, in which case, I’ll take two, thanks.)

If you’re not directly addressing someone in the second person, but describing events in the third person, then please do NOT use a comma.

✘   We asked Mr. President, to wrap up

✘   Sam, is the greatest.

✘   Fido, lay down.

✔︎   We asked Mr. President to wrap up

✔︎   Sam is the greatest.

✔︎   Fido lay down.

Commas in the wrong places can feel like sand in your knickers after a trip to the beach. Here’s another time where commas go astray…

What is comma splicing?

Comma splicing is a messy business. It describes the problem of taking two grown ass independent clauses and trying join them together with a flimsy comma. Like trying to fuse two wooden beams with some sticky tape, you need something a bit more substantial to carry the weight.

✘  Vanilla is the best ice cream flavour, it’s no good arguing.

✘  The sun is finally out, I’m heading to the garden.

✘  Dev went to the party, it seemed fun.

When it comes to how to avoid comma splicing, if both sides of the comma have an independent clause, what you actually need is a connective, a full stop, or a semi-colon. An independent clause can be a complete sentence, so you’ve got to treat it like a sentence. If you’re choosing to join two independent clauses and not keep them as separate sentences, use a comma with a connective. They simply cannot be threaded together with commas. Sorry!

A final thought on commas

There’s no doubt that commas can be tricky. In fact, I imagine you could find at least 20 instances in this post where you disagree with my inclusion or omission of a comma.

My final advice is that if in doubt, leave it out. Comma splices are far more unsightly and interrupting than missing commas, so err on the side of caution.

Well done for sticking with it. I hope you haven’t slipped into a comma! (Oof. Don’t worry: I’ll show myself out.)

Becky Kleanthous

Copywriter hire UK