Apostrophes are like grenades: You should only use them if you really, really know how. Since you’re much more likely to run into an apostrophe in your daily life than a grenade (hopefully), it’s best to master the apostrophe rules before you hurt an innocent sentence. And good news: There are only two that you need to remember.
An apostrophe (pronounced ah-pah-stroh-fee) is a small punctuation mark near the top of a line of writing ('). Apostrophes look like single quotation marks, but they’re used alone rather than in pairs.
Apostrophes mainly indicate that letters have been omitted, or they show a noun’s possession. Occasionally, they can show that a single letter or number is plural.
Apostrophes appear in lots of different words, especially in informal writing. It’s not uncommon to see two or more apostrophes in the same sentence.
- Mike’s dad said that he can come over.
- Aren’t you the same people who bought my house?
- I’d love to join your team, but I’m afraid I can’t.
- It’s not fair — Ken always gets the best stuff!
The first main function of apostrophes is to replace missing letters in a word. These words are either contractions or shortened versions of other words.
Contractions are combinations of two other words in informal writing. Most contractions combine the words have, will, would, are, is, and not with other words.
- I’ve never seen that movie before. (Apostrophe replaces the “ha” in I have)
- He’ll be there tomorrow. (Apostrophe replaces the “wi” in He will)
- They’d come to the party if they could. (Apostrophe replaces the “woul” in They would)
- We’re on our way to the campsite. (Apostrophe replaces the “a” in We are)
- Andre’s talking about his new job. (Apostrophe replaces the “i” in Andre is)
- The boss isn’t available until Monday. (Apostrophe replaces the “o” in is not)
- Let’s meet sometime next week. (Apostrophe replaces the “u” in Let us)
When you shorten other words in written dialect or casual writing, the apostrophe can replace those missing letters as well.
- We went swimmin’ all afternoon. (Apostrophe replaces the “g” in swimming)
- Cheer up — ‘tis the season for happiness! (Apostrophe replaces the “i” in it is)
- ‘Fraid I can’t help you today. (Apostrophe replaces the “a” in afraid)
The next main function of an apostrophe is showing possession, but it’s actually just an extension of the “omitting letters” function. Writers used to show possession by adding -es to the end of a noun, long before spelling conventions made -es a plural noun form.
They began using apostrophes to omit the “E” in these possessive nouns — which is how we get possessive nouns with an apostrophe and “S” at the end.
When a singular noun has possession over another noun (such as Mom’s hat or the boy’s dog), add an apostrophe + “s” to the end of the noun. The same goes for collective nouns and plural nouns that don’t end in “s.”
- The cat’s kittens all began meowing at once. (cat is singular)
- Something’s wrong with Lyle’s computer. (Lyle is singular)
- Our team’s uniforms are green and blue. (team is collective)
- My friend’s family eats dinner together every right. (family is collective)
- The waiter served the women’s meals. (women is plural, but doesn’t end in “s”)
- The children’s room was perfectly clean. (children is plural, but doesn’t end in “s”)
When the noun is plural and already ends in “s,” just add the apostrophe at the end.
- My parents’ house is just around the corner.
- Let’s go meet the Smiths’ new baby.
- Don’t throw away the kids’ art project.
It’s the age-old question: Should you add apostrophe + “s” to singular words that already end in “s” (such as James, cactus, or dress), or just an apostrophe?
The answer is that both solutions are correct. It depends on your style guide and your personal preference.
- Curtis’ teacher asked for his homework. (Correct)
- Curtis’s teacher asked for his homework. (Correct)
- The class’ pet bunny was missing. (Correct)
- The class’s pet bunny was missing. (Correct)
The only exception is for words that are the same in singular and plural forms, such as scissors or Mercedes. Add only an apostrophe after these words, since adding another “s” would result in an incorrect pronunciation (such as scissors’s becoming scissorses, which is not a word).
What happens when two nouns possess the same thing? Add an apostrophe + “s” to only the second noun if they both own the exact same item.
- Dave and Alice's car needs service. (Both Dave and Alice own the car)
- Tim and Jane's trip was amazing. (Tim and Jane went together on the trip)
- Darnell and Dylan's business is doing well. (Darnell and Dylan own the same business)
However, if each noun owns their own version of the same item, then add an apostrophe + “s” to each noun (and make their items plural).
- Dave’s and Alice's cars need service. (Dave and Alice each own a different car)
- Tim’s and Jane's trips were amazing. (Tim and Jane took separate trips)
- Darnell’s and Dylan's businesses are doing well. (Darnell and Dylan each have a separate business)
You may also see apostrophes when a writer is describing plural lowercase letters or numbers. This is the only situation where apostrophes can show plurals, and it’s only to prevent confusion — though some style guides, including APA style, do not advise using apostrophes in this way.
- I added too many a’s to the “Happy Birthday” sign.
- Be sure to dot your i’s when writing in cursive.
- How many 2’s are in 2022?
One of the most common grammatical errors involves mixing up its and it’s. Its (no apostrophe) shows possession, and it’s (with an apostrophe) is a contraction for it is.
- The fish swims around its bowl. (Possessive)
- The fish swims around because it’s hungry. (Contraction)
But wait — if its shows possession, shouldn’t it have an apostrophe? No, because its is a possessive modifier and pronoun, not a possessive noun. Possessive pronouns such as his, hers, yours, or ours also don’t include an apostrophe. But it’s, like all contractions, does have an apostrophe.
The term apostrophe is a big word for such a little punctuation mark — and it doesn’t initially come from grammar. Derived from the Greek apostrephein, meaning “to turn away,” apostrophe was initially a literary device in which a character makes a speech to someone who isn’t present (thus “turning away” from the scene).
The punctuation definition of apostrophe comes from the absent nature of the audience of these speeches. Just like the person a character is speaking to, the letter replaced by an apostrophe isn’t there.
Deciding when to use an apostrophe can seem trickier than determining when not to use an apostrophe, but it’s really not. Some tips to remember:
- Is the apostrophe replacing anything? No? Then don’t use it.
- Is the apostrophe showing the noun owning anything? No? Then don’t use it.
- Would the sentence be confusing without an apostrophe? No? Then don’t use it.
- Are you writing a holiday card and adding an -s or -es to your last name? Don’t use an apostrophe (it's always wrong).