Apostrophes are those little curved marks you see hanging from certain letters. They look harmless enough, so why do even well educated people throw them where they don't belong and leave them out where they're needed? Until apostrophes disappear from English altogether, you can take one step toward apostrophe reform by perfecting the art of showing possession.
Most other languages are smarter than English. To show possession in French, for example, you say
the pen of my aunt
the letters of the lovers
the fine wines of that corner bar
and so on. You can say the same thing in English too, but English has added another option, the apostrophe. Take a look at these same phrases — with the same meaning — using apostrophes:
my aunt's pen
the lovers' letters
that corner bar's fine wines
All of these phrases include nouns that express ownership. Think of the apostrophe as a little hand, holding on to an s to indicate ownership or possession. In these examples, you notice that the apostrophe is used to show that a singular noun owns something (aunt's, pen; bar's fine wines). You also see a phrase where the apostrophe indicates that plural nouns own something (lovers' letters).
Ownership for singles
Here's the bottom line: To show possession by one owner, add an apostrophe and the letter s to the owner:
the dragon's burnt tooth (the burnt tooth belongs to the dragon)
Lulu's pierced tooth (the pierced tooth belongs to Lulu)
Another way to think about this rule is to see whether the word of expresses what you're trying to say. With the of method, you note
the sharp tooth of the crocodile = the crocodile's sharp tooth
the peanut-stained tooth of the elephant = the elephant's peanut-stained tooth
and so on.
Sometimes, no clear owner seems present in the phrase. Such a situation arises mostly when you're talking about time. If you can insert of into the sentence, you may need an apostrophe. To give you an idea of how to run the "of test," here are some phrases that express time:
one week's tooth cleaning = one week of tooth cleaning
a year's dental care = one year of dental care
When you're talking about time, give your sentence the "of test." If it passes, insert an apostrophe.
Pop quiz
Which sentence is correct?
A. Lulu told Lola that Lochness needs a years work on his gum disease.
B. Lulu told Lola that Lochness needs a year's work on his gum disease.
Answer. Sentence B is correct because Lochness needs a year of work on his mouth. (Actually, he needs false teeth and a nose job, but the year's gum work is a start.)
Because Bill doesn't own everything: Plural possessives
You'd be finished figuring out apostrophes now if everything belonged to only one owner. Bill Gates is close, but even he hasn't taken over everything yet. You still need to deal with plural owners. The plurals of most English nouns — anything greater than one — already end with the letter s. To show ownership, all you do is add an apostrophe after the s. Take a look at these examples:
ten gerbils' tiny teeth (the tiny teeth belong to ten gerbils)
many dinosaurs' petrified teeth (the petrified teeth belong to a herd of dinosaurs)
a thousand sword swallowers' sliced teeth (the sliced teeth belong to a thousand sword swallowers)
The "of test" works for plurals too. If you can rephrase the expression using the word of, you may need an apostrophe. Remember to add the apostrophe after the letter s.
three days' construction work on Legghorn's false teeth = three days of construction work
sixteen years' neglect on the part of Lulu's dentist = sixteen years of neglect
two centuries' pain of rotten teeth = two centuries of pain
Pop quiz
Which is correct?
A. The Halloween decorations are decaying, especially the pumpkins teeth. Cedric carved all ten jack-o-lanterns, and he can't bear to throw them away.
B. The Halloween decorations are decaying, especially the pumpkins' teeth. Cedric carved all ten jack-o-lanterns, and he can't bear to throw them away.
C. The Halloween decorations are decaying, especially the pumpkin's teeth. Cedric carved all ten jack-o-lanterns, and he can't bear to throw them away.
Answer: Sentence B is correct. The context of the sentence (all ten jack-o-lanterns) makes clear the fact that more than one pumpkin is rotting away. In sentence B, pumpkins' expresses a plural possessive. In sentence A, pumpkins has no apostrophe, though it clearly shows possession. In sentence C, the apostrophe is placed before the s, showing a single pumpkin.
Irregular plural possessives
In many of the examples you've just read, you'll find the word "teeth." Look at the word teeth. It is plural, but teeth doesn't end with the letter s. Teeth is an irregular plural. To show ownership for an irregular plural, add an apostrophe and then the letter s (teeth's). Check out these examples:
teeth's cavities (The cavities belong to the teeth.)
children's erupting teeth (The erupting teeth belong to the children.)
the women's lipstick-stained teeth (The lipstick-stained teeth belong to the women.)
geese's missing teeth (No teeth belong to the geese, because as of course you know, birds have beaks instead. Geese have serrations on their bills that look like teeth.)
Compound plural possessives
What happens when two single people own something? They go to court and fight it out, that's what happens! But forget lawsuits. The grammatical answer is one or two apostrophes, depending upon the type of ownership. If two people own something together, as a couple, use only one apostrophe.
Hillary and Bill Clinton's daughter (Chelsea claims both of them as her parents.)
Ludwig and Ludmilla's wedding (The wedding was for both the blushing groom and the bride.)
Lochness and the superspy's secret (Lochness told it to the superspy, so now they're sharing the secret, which concerns doughnuts and explosives.)
If two people own things separately, as individuals, use two apostrophes:
Lulu's and Legghorn's new shoes. (She wears size 2, and he wears size 12. They definitely own separate pairs.)
Eggworthy's and Ratrug's attitudes towards dieting. (Eggworthy doesn't know and doesn't care to know his cholesterol count. Ratrug carries around a nutrition chart and a scale and weighs every scrap of food he eats.)
Cedric's and Lola's fingernails. (He has his; she has her own; both sets are polished and quite long.)
Not every plural noun has an apostrophe
Remember that an apostrophe shows ownership. Don't use an apostrophe when you have a plural that is notexpressing ownership. Here are some examples:
RIGHT: Bagels stick to your teeth.
WRONG: Bagel's stick to your teeth.
WRONG: Bagels' stick to your teeth.
Look at another set:
RIGHT: The gnus gnashed their teeth when they heard the news.
WRONG: The gnus' gnashed their teeth when they heard the news.
WRONG: The gnu's gnashed their teeth when they heard the news.
If the plural noun is not showing ownership, don't use an apostrophe. If the plural noun shows ownership, do add an apostrophe after the s (for regular plurals). For irregular plurals showing ownership, add 's.
See also:
How to Show Possession with Proper Nouns
