I know punctuation was one of your favourite things at school, right up there with long division, but there’s often confusion over certain points. I’ve put together the examples below to help clarify some of these, as a misplaced apostrophe or hyphen can cause all manner of problems.

COMMAS

Commas are widely misunderstood, and generally underused by those writing in an academic context. Common misconceptions are that they should be used “when you take a breath” and that they “shouldn’t be used before and…”. You should use commas to separate different pieces of information within a sentence. Here’s an example:

There is widespread misunderstand regarding use of commas and apostrophes, and both are important to ensure clarity in writing.

You’ll see that the comma in the above sentence is used before and to separate two distinct pieces of information.

APOSTROPHES

These can be pesky little blighters that can cause all manner of confusion, but they’re essential to clarify meaning. Hopefully the examples below will help you get to grips with them.

The chair’s leg is broken.
Chair’s – this is a possessive: it is the leg of the chair.

Chairs’ legs are often broken.
Chairs’ – again a possessive, but this refers to the legs of multiple chairs; legs does not have an apostrophe as this is simply the plural of leg.

The chair’s got a broken leg.
Chair’s – this is chair has, different from the possessive chair’s above.

The chair’s broken.
Chair’s – the chair is broken.

Someone should really mend these chairs…
No apostrophe for chairs here, as this is simply the plural of chair.

The kids’ bedroom is untidy.
Kids’ – this is the bedroom of more than one kid.

The kid’s bedroom is untidy.
One lazy kid who can’t tidy a room.

The children’s playground…
Children’s – apostrophe-s here, as children is already a plural. Similarly, the people’s champion.

There can be confusion over whether to put an apostrophe before or after the s regarding names, etc. Officially, if there’s an s then the apostrophe goes after, but there’s also a school of thought that this only applies if the s actually has a z sound:

James’ coat was wet.
James ends in a z sound.

Thomas’s coat was wet.
Thomas ends in an s sound.

However, if you’re referring to a brand or company that has an apostrophe, then you have to keep it:

McDonald’s’ burgers are very popular. Similarly, M&M’s’ market share…

ITS, IT’S and ITS’

OK, the easy one first: its’ does not exist. Never has, never will. So, that established…

It’s is only ever it is or it has.

The chair’s broken: it’s one of the legs.

Here we’ve got chair’s for chair is, then it’s because we’re saying it is one of the legs. The colon separates the statement from the reason (more on that later).

The chair’s wobbly; I think its leg is broken.

Chair’s here shortens chair is, but there’s no apostrophe for its, because we’re not saying it is or it has. There’s a semi-colon for the run-on sentence.

If unsure just ask yourself whether you’re saying it is or it has. If not, then its.

COLONS AND SEMI-COLONS

Use a colon to indicate a list, reason or example to follow:

There are three primary colours: red, yellow, blue.

Unattended belongings will be removed after 30 minutes: this is a security issue.

Also use semi-colons to separate several longer clauses after a colon:

Today the student asked me about punctuation, and we covered several points in depth: the correct way to use an apostrophe in several contexts; use of a semi-colon in run-on sentences and to separate clauses; the difference between hyphens and dashes.

Also use a semi-colon with a run-on sentence:

Library attendants regularly patrol the building; unattended belongings will be removed after 30 minutes.

HYPHENS AND DASHES

Use hyphens to join related words:

Peer-to-peer sharing… / One-to-one tutorials… / This is a long-term trend.

However, examples like the latter can be context-specific, so:

The trend is evident over the long term.

Dashes can be used to indicate text that deviates from the main point:

Apostrophe use needed some explaining – so many variations! – but we got there in the end.

But use brackets for supporting information:

The Cold War (1947-1991) was a state of geopolitical tension between the Soviet Union with its satellite states, and the United States with its allies following World War II.

AND FINALLY…
Some spelling mistakes are invisible to the spell-checker, and other words are commonly misused for one reason or another. Here are some to look out for, and a few examples of unnecessary text.

• form / from – a classic, easily missed.
• manufactures / manufacturers – a manufacturer manufactures, but the rs at the end can hide an error.
• program / programme – in British English a program is only ever computer software; for something entertaining on telly, a series of events or a theatrical souvenir, it’s programme.
• public / pubic – a missing “l” makes all the difference here. You wouldn’t want to embarrass yourself in a pubic place now would you.
• aging / ageing – all over the world populations are ageing. Our American cousins are happy to go with aging, but that reads a bit too much like gagging, so add the e to soften the g.
• convenient store / convenience store – a convenience store is a small grocery shop; if it’s nearby and sells what you want, when you want it, then it’s also convenient.
• customer / costumer – here a transposed o and u turn someone buying goods or services into someone who designs pantomime outfits. Oh no it doesn’t! Oh yes it does! etc.
• loosing / losing – loosing indicates untightening (although loosening would be better), while losing is the process of loss: The man was losing patience with punctuation.
• off of and gotten – both horrible Americanisms; avoid (unless you’re American, writing in America).
• skyrocketing – widely used, but conjures up a somewhat comical image; soaring is much better.
• mid-end – you can’t have a “mid-end”, because if it’s in the middle it’s not at the end; try mid-range, mid-price or similar instead.
• every day / everyday – every day = each day; everyday = ordinary: Every day I write the book; it’s the story of an everyday guy. Every day I go to the supermarket: it has everyday low prices.
• forecasted – just use forecast, okay?
• countries around the world – where else would they be? Just countries.
• going forward – usually completely unnecessary, for example: This could change going forward if the company provides an incentive for consumers. This reads much more concisely as: This could change if the company…
• continues to remain – The company continues to remain the leader in its market. Much tighter as The company remains…

This is by no means exhaustive but might help someone along the way. A confused member of the writing pubic, perhaps. Feel free to add other suggestions in the comments.

I’m a writer and Royal Literary Fund Fellow.
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