How do I use a possessive apostrophe when the word ends in 's'?

Apostrophes can be trying at the best of times, but when the word ends in 's' it gets particularly confusing. How do you know where to put the apostrophe? And what about an extra 's'. Do you need it? The simple fact is that tastes in punctuation have changed over time and now we are left with a headache as we try to follow the rules we were taught all those years ago (well, it was a wee while ago for me, but perhaps not for you).

When the possessing noun is plural and ends in 's' just put the apostrophe after the 's' and then move on. (Some plural noun examples, teachers, shopkeepers, sisters, bosses, but not firemen as although it is plural it doesn't end in 's'.)

All the teachers' pupils ran the cross country run today. Not one of those teachers accepted an excuse. Every child had to run.

The shopkeepers' concerns were unfounded. None of the shopkeepers needed to worry about their shared concerns, after all.

When the sisters' chores were done they were free to annoy their little brother. Those sisters had too much time on their hands. More chores, I say.

The bosses' combined pay would have kept me in champagne for the rest of my life. Are those bosses really worth all that money?

So far, so good. But when you are writing a person's forename or surname things can vary a little and get vague.

The name Jesus and names from the ancient world that end in 's' just take an apostrophe and no extra 's'. I should mention that some people (and countries) include other biblical names in this rule too. Some don't. Examples of names that fall under this rule are Archimedes, Achilles and, well, Jesus.

Hercules' labours were laborious. Well, they must have been or they wouldn't have been called labours, would they?

Names that end in an 'iz' sound (that's called a voiced 's') need an apostrophe and then an 's' added.  

Les's friends never know where to put the apostrophe in his name. They were pretty certain it wasn't Le's.

Names that end in 'ss' need an apostrophe and an 's'.

Mr Moss's house was painted moss green.

But, if you are writing about the Moss family's house you would drop the extra 's' because (...see the first rule at the top) it would be a plural. Like this:

The Mosses' house was painted moss green. Some people like moss green.

So what about all the other names that end in 's'? Lynne Truss, in Eats, Shoots & Leaves refers to Fowler's Modern Usage and offers the following:

...modern names ending in 's' (including biblical names, and any foreign name with an unpronounced final 's'), the 's' is required after the apostrophe.

Lynne Truss's book is an invaluable resource on apostrophes. Yes, indeed!

She used Alexander Dumas's name as an example in her book. I stole that one because I couldn't think of another foreign name with a silent final 's' off the top of my head.

This whole business is messy. It is complicated. Don't worry if your head hurts a little just thinking about it. But next time you need to place an apostrophe just re-read those rules and place that apostrophe with confidence.
 

When do I stop?

In many parts of the world it is called a full stop. In the US it is called a period. We used to see them a lot more than we do these days. Where have they gone? And when do we use them? There's a summary at the bottom if you want to go to the cheat sheet. Otherwise...

You need one at the end of a sentence. It tells us to stop, take a breath and then move on to the next sentence. Everyone knows that, right? Well, yes, but sometimes when we are writing we get confused about where one sentence ends and another begins. That's when we end up with a run-on sentence. For example:

It was raining hard my umbrella was at the bottom of my school bag.

The two ideas just don't go together in that one sentence. Don't you miss that pause a full stop gives you? You need something to go between those two ideas. A full stop would be perfect:

 It was raining hard. My umbrella was at the bottom of my school bag.

Easy! So what else needs a full stop? In Commonwealth countries the answer to that used to be quite complicated. But now we seem to be aiming for a less cluttered look in our writing, with full stops among the first to go. 

The only abbreviation we still use a full stop for is 'no.' for 'number' (strictly speaking it isn't an abbreviation but a contraction of the word numero). The full stop is there to ensure 'no.' doesn't get confused with 'no'. Just remember to leave the full stop out if you are referring to more than one number ('nos'). 

Finally, we still use the full stop in some Latin abbreviations. It pays to check your dictionary for these. Sometimes a dictionary will have two choices. Just go with the first option as that is the more common usage. The most common Latin abbreviations we use are punctuated like this:

• a.m. (or am)
• p.m. (or pm)
• e.g.
• i.e.
• etc.
• c. 
• NB
• PS 

What do you need to remember when using a full stop?

1. Use it at the end of a sentence to tell your reader to take a pause.
2. Use it to avoid run-on sentences.
3. Use it for 'no.' (number).
4. Use it for some Latin abbreviations (check your dictionary).

How do I know if it's 'its' or 'it's'?

Okay, this one stumps people because it seems so counter-intuitive. Let's look at a couple of sentences.

The cat licked its tummy.

 It's a black cat.

Many people want to put an apostrophe in that first sentence because, after all, don't we use an apostrophe to show possession? Well, yes, but unfortunately that is where English grammar starts to get ugly because the 'its' in that first sentence is actually a possessive determiner and they don't take apostrophes.

Before you run for the hills, it's okay, I've stopped the heavy grammar talk right there. All you need is one nice easy rule:

If it's short for 'it is' or 'it has' then use an apostrophe. For everything else just leave out the apostrophe.

So let's check the sentences near the start of this post.

'The cat licked it is/it has tummy' is obviously wrong. The sentence must be 'The cat licked its [own] tummy' so 'its' without an apostrophe is the way to go.

 'It is a black cat' makes perfect sense so we can use 'it's' with an apostrophe.

It's that easy!