1. Apostrophe Rules

2. Non-apostrophe rule…
Some words are possessive by definition, and do not need an apostrophe… even if there is an “S” in the word. Our books are renewed. Those renewed books are ours. Their opinions do not matter to me. Those opinions are theirs, not mine. Whose opinion is that? Those opinions are hers! The desk lay on its side after the classroom kerfuffle.

3. Rule #1a
If you have to add an “S” to make something possessive, then you have to put an apostrophe BEFORE the “S”. Jordan’s poem… Sophia’s backpack… The boy’s coat (one boy)…

4. Rule #1b
If you have to add an “S” to make something possessive, but it’s a word/name that ends in “S” then you either add an ‘s (just like rule 1a) or you can put the apostrophe after the “S”. Jesus’s disciples or Jesus’ disciples Chris’s books or Chris’ books

5. Rule #2
If you have to add an “S” to make something plural, and it is also a possessive, the apostrophe goes AFTER the “S” The three boys’ mothers are part of the PTA. The ten students’ lockers are broken. The six cell phones’ batteries are charged.

6. Rule #3
If a word is already plural without having to add an “S”, then you simply add an apostrophe before the “S” just as in rule #1a. The children’s toys… The women’s boots… The people’s opinions…

7. Rule #4
If a two or more people share possession of something, put the apostrophe “S” on the last person’s name in the list. Mary and John’s house… (they live in the same house) Emma, Joe and Mia’s presentation… (They all presented together as a group.)

8. Rule #5
If a two or more people have different possession of something in common, put the apostrophe “S” on the last person’s name in the list. Mary’s and John’s house (they live in separate houses. Emma’s, Joe’s, and Mia’s presentations (each presented individually)

9. There are others: Contractions…
Use apostrophes to contract words: Can’t (Cannot) Don’t (Do not) Won’t (Will not) In the ‘80s, people had big hair.

10. There are others: Single Letters or Sometimes Numbers …
She earned all A’s on her report card. He made 4’s on his essay rubric. He made all 4s on his essay rubric.

11. There are others: Time and Money
 Amounts of time or money are sometimes used as possessive adjectives that require apostrophes.
Incorrect: three days leave Correct: three days' leave Incorrect: my two cents worth Correct: my two cents' worth

12. Beware False Possessives!
Beware of false possessives, which often occur with nouns ending in s. Don't add apostrophes to noun-derived adjectives ending in s. Close analysis is the best guide. Incorrect: We enjoyed the New Orleans' cuisine. In the preceding sentence, the word the makes no sense unless New Orleans is being used as an adjective to describe cuisine. In English, nouns frequently become adjectives. Adjectives rarely if ever take apostrophes. Incorrect: I like that Beatles' song. Correct: I like that Beatles song. Again, Beatles is an adjective, modifying song. Incorrect: He's a United States' citizen. Correct: He's a United States citizen. United States explains what country he is a citizen of.