Common comma rules

A punctuation mark that is used across many languages, the comma marks a quick little break in the text, adding structure. It also has uses for separating items in a list, words, phrases or other clauses, or any other purpose other than ending a sentence.

We’ll be aiming to cover some many of the widely-used rules around comma usage, including some examples which show them clearly and the reasonings as to why – and where – you may want to use them.

Serial comma / Oxford comma

Separating items in a list with commas is easily done – just think of all the writers, proofreaders, marketing professionals, editors, and more who do it daily! But the Oxford comma is reserved to go before the co-ordinating conjunction – in this example, the word ‘and’.

It isn’t necessarily wrong to use or avoid using the Oxford comma; but rather, a matter of choice. Many publications disparage its use due to it being redundant (though in some cases it can be required) or sometimes stylistically avoided – but depending on a whole heap of factors, it is largely up to personal choice!

With co-ordinating conjunctions

As above, commas can be used just fine with co-ordinating conjunctions – especially when it is joining independent clauses together. See the examples below:

‘Jay is a lively boy, but he loves to nap!’ uses a comma to join two opposing statements.

‘Luna is silent but ruthless’ doesn’t need a comma as the clauses aren’t independent. 

Commas in lists

When listing a large amount of items in succession, especially when reading aloud, it will be normal to take a break or two for breath. Commas are used between list items to mark the differentiation between one and the next: like if we were going to list colours like red, blue, yellow, green, and brown.

Comma splice mistakes

Here’s where things can get confusing – using a comma mistakenly when a conjunction or semi-colon (or even a new sentence) would have done the job is called a ‘comma splice’. Unfortunately, the comma alone doesn’t have strong enough powers to join two opposing statements so the sentence becomes a mishmash of two phrases stapled together instead of a grammatically correct statement.

‘The snails were out in force; I had to dodge around them’ makes much more sense with a semi-colon instead of a comma.

Clauses and commas

Extra information stuffed into a sentence, which can neatly be contained within a pair of commas, is an example of a non-restrictive clause. You would be able to remove the inner clause and retain the sense of the sentence, which wouldn’t be the case for a restrictive clause. Restrictive clauses don’t need their own set of comma separation as the information they add in is needed to understand the sentence – 

‘Here’s the car, that I saw earlier, speeding away’ becomes clunky with the added commas and could do without them entirely!

Commas and multiple adjectives

When listing adjectives that all rank similarly in importance, it can be tricky to work out whether commas are needed or not. Switching up the order in which they appear can be a good way of working out whether they are coordinate – as you’ll be able to see if the sentence still makes sense with them in a different order.

The tangy, irresistible scent of a citrus perfume wafted past.

Her hatred grew for the frustrating, unaware, immovable person in her way.

Come again?

Hopefully commas will be a little easier to understand and implement once a few of the major usage rules have had some time to ruminate in your brain. It can be tricky – and not all of them have been covered in this article – but a good rule of thumb is to place commas where you’d take a breath!