So small, the humble comma, and surely so simple. Everyone can work out when to use a comma, can’t they?

Well, for those who aren’t sure, here are some tips.

For starters, commas are used to separate things like names, quotations or questions from the rest of a sentence:

  • Have a biscuit, Potter. 
  • I asked my mother, “What will I be?
  • They shoot horses, don’t they?


Commas are also used to ‘fence off’ extra, non-essential information, just like parentheses (brackets to you and me):

  • Shoot all the blue jays you want, if you can hit ’em, but remember that it’s a sin to kill a mockingbird.
  • It was, as far as I could tell, the best option.
  • I have just one day, today, and I’m going to be happy in it.

And that’s not all. The comma can also be used to join two independent clauses together, but only if you put in a coordinating conjunction. (See what I did there?)

Comma plus coordinating conjunction (for, and, nor, but, or, yet or so – FANBOYS is a useful mnemonic) equals a properly connected sentence: He told a joke, yet she didn’t laugh.

But if you take away the yet, you have a ‘comma splice‘: He told a joke, she didn’t laugh.

To fix the sentence, you now need a semicolon (or even a dash) instead: He told a joke; she didn’t laugh.

Comma splices are the kind of crime English teachers and other sticklers like to jump up and down about. But there are worse mistakes – especially when you’re churning out emails and bashing out texts in a punctuation-indifferent office environment. I mean, it’s not as if you’ve put an apostrophe in ‘Open on Tuesdays’…

But sometimes, leaving out a single comma can lead to horrible misunderstandings. Common examples of comma horror include:

  • Eats shoots and leaves (a panda) v eats, shoots and leaves (Clint Eastwood)
  • I love cooking, my family and my dog (mum) v I love cooking my family and my dog (serial killer)

Punctuation is the good manners of writing. Use it well and it will show that you are all about attention to detail. If you punctuate well, you’re probably the kind of person who brushes their teeth, ties a tidy shoelace, turns up to work on time, uses please and thank you, and reads the instructions first.

Of course, good writers tend to know when to apply the rules and when to bend, stretch, or even just plain ignore them to create the desired effect.