Once again my 9 year old daughter’s homework has prompted me to think about language and learning, as in earlier pieces about Adverbs and Homophones. She has studied apostrophes before and it was part of her homework again last week.

It’s a good example of something where the broad principles are straightforward, and can be taught easily, but complications arise from the detail, and from what might seem like exceptions. It’s also a subject that can be covered in one or two sides of A4 paper. You don’t need to read a whole book to understand about apostrophes.

Based on the amount of times people write “it’s” instead of “its” on web pages this is clearly something that many adults still have trouble with.

The two broad principles are that apostrophes are used to indicate missing letters or to indicate ownership (that is, that something belongs to a person or thing).

Missing letters

The phrase “It’s hot” is short for “It is hot”, so the apostrophe indicates that there’s a missing letter (the “i” from “is”), and earlier in this sentence “there’s” is short for “there is”, for the same reason.

“They’re” is short for “They are”, “We’re” is short for “We are”, “You’re” is short for “You are” and so on.

“It’s been a long time” is short for “It has been a long time”, so sometimes an apostrophe indicates that there is more than one missing letter.

Occasionally this kind of abbreviation – using an apostrophe to indicate missing letters – also results in the word being changed, for example “will not” becomes “won’t”. In a word like “shan’t” (instead of “shall not”) there is only one apostrophe, even though there are two letters missing at the end of “shall” as well as the “o” in “not”. In centuries past you might have written “sha’n’t” but you don’t have to do that now: things have become easier, grammatically.

Ownership

Apostrophes to indicate ownership (possessive forms) are straightforward to begin with: the name of the person that something belongs to, an apostrophe, and the item they own, for example “Anna’s football” or “Jacob’s book”.

The same principle applies with anyone or anything that “owns” something, even if that thing is abstract (something you can’t touch) rather than concrete (something you can touch): “the girl’s favourite TV programme”, “the boy’s behaviour” or “the software company’s plans for global domination”.

Ownership and time

This concept of ownership starts to get complicated when dealing with time. In a phrase like “Anna’s football” there are two clearly indicated nouns, a girl and her football, which makes it straightforward. The phrase “one week’s time” has an apostrophe, to show that the time that has to pass (abstract concept) belongs to one week. Other examples include “one year’s time” and “a day’s holiday”.

Ownership and plurals

Things also get complicated when you start dealing with plurals and possessive apostrophes.

“The girl’s football” indicates a football belonging to one girl. “The girl’s footballs” indicates more than one football belonging to one girl. But if there are many footballs, belonging to many girls, the apostrophe goes after the word “girls”, as follows: “The girls’ footballs.”

“The girls’ football” suggests that many girls are sharing one football. “The girls’ football lesson” tells you that there is more than one girl having a football lesson.

[This paragraph has over 140 words explaining the difference between Queen’s College Oxford and Queens’ College Cambridge. Many of the colleges in Oxford and Cambridge were founded by, or named in honour of, kings, queens or saints: King’s College Cambridge was founded by Henry VI; Queen’s College Oxford was named in honour of Queen Philippa of Hainault, the wife of Edward III. Queens’ College Cambridge, on the other hand, was founded by Margaret of Anjou (wife of Henry VI) and re-founded by Elizabeth Woodville (wife of Edward IV) and because it’s named in honour of two queens it’s spelt “Queens’ College” rather than “Queen’s College”. Even without the history lesson you can tell that Queen’s College Oxford is named in honour of one queen and Queens’ College Cambridge in honour of more than one because of where the apostrophe is placed.]

If the word is plural but doesn’t end in “s” (like men, women and children) the possessive form is like a singular noun – the word, an apostrophe and then the letter “s”: “men’s clothing”, “women’s health”, “children’s parties”.

Ownership and time (plurals)

Putting together the last two points, the phrase “two weeks’ time” has the apostrophe as indicated, after the word “weeks”. The time belongs to two weeks rather than one. The expression “Two Weeks’ Notice” is similar. “Two Weeks Notice” (without the apostrophe) was a film featuring Hugh Grant and Sandra Bullock; its title prompted Lynne Truss to add apostrophes with marker-pen to movie posters when it came out, around the time that she wrote “Eats Shoots and Leaves”.

Its and It’s

The other complication regarding ownership and apostrophes is the word “its”, which might seem like an exception. “Its” (without an apostrophe) indicates ownership, as in the phrase “its title” in the previous paragraph, or “the software company and its plans for world domination”. But “its” is a possessive pronoun, like my, your, his, her, our or their, and they don’t have apostrophes either. (“You’re” is short for “You are”, but “your” indicates that something belongs to you: your happiness, for instance, or your favourite colour. “You’re getting bored now” is short for “You are getting bored now”.)

The simple rule is that “it’s” (with an apostrophe) always indicates at least one missing letter, not possession. If you can’t replace the word “its” with “it is” or “it has” then it shouldn’t have an apostrophe.

Here’s an example. “Microsoft’s staff” is correct and so is “Microsoft and its staff”. If you replace the word “its” in that last sentence with “it is” or “it has” it doesn’t make sense, so there’s no apostrophe.

James’s or James’

When a name ends in “s” (like James) the possessive form can either be James’s or James’: both are correct, depending on house style. If you have a choice about which form to use the best advice is to be consistent: make your choice and stick with it. However, different places with the same name might be spelt differently. The park next to Buckingham Palace here in London is called “St James’s Park” and so is the nearby tube station. The home ground of Newcastle United Football Club is “St James’ Park”. If a place-name has a convention it’s best to stick with it.

And that’s about it. Everything you need to know about apostrophes is in the thousand words above, so it would fit on three sides of A4. With fewer examples and less explanation, as in the Summary below, you can get it all onto a single side of A4.

Summary

Abbreviations: it’s, we’re, you’re, they’re, won’t, shan’t;

Possessives (singular): Anna’s football, Jacob’s book, Microsoft’s staff, a week’s holiday;

Possessives (plural): the girls’ footballs, two weeks’ notice, Queens’ College Cambridge; men’s clothing, women’s health;

It’s and its: it’s is always short for “it is” or “it has”; “its” is possessive, as in “Leicester City Football Club and its remarkable achievement”.