Rule 1: Contractions & Omitted Letters
Use an apostrophe with a contraction in the place of the omitted letter.
- don’t-> do not
- isn’t-> is not
- You’re right ->You are right
- She’s a great teacher-> She is a great teacher
Rule 2: It’s vs. Its
The only time an apostrophe is used for it’s is when it is a contraction for it is or it has.
“Its” indicates possession but does not require an apostrophe.
- It’s a nice day ->It isa nice day.
- The cat opened its mouth to yawn. ->Indicates possessive (the mouth belongs to the cat), so no apostrophe.
Rule 3: Singular possession
Use an apostrophe before the “s” to show singular possession (something belonging to one person).
Note: Although names ending insor anssound are not required to have the seconds added in possessive form, it is preferred.
- one woman’s hat
- the actress’s fan
- one child’s candy
- Mr. Jones’s book
- Texas’s weather
- Ms. Straus’s daughter
Rule 4: Plural possession
To show plural possession, form the plural of the noun and then add the apostrophe.
- two boys’ hats
- all of the actresses’ costumes
- the families’ houses
Rule 5: No substitution for plural
Do not use the apostrophe in place of the plural.
- We visited the Sanchezes in Los Angeles.
- The Changs have two cats and a dog.
- We carried all of the cartons up two flights of stairs.
Rule 6: Singular compound nouns
With a singular compound noun, show possession with apostrophe + s at the end of the word.
- My mother-in-law’s new car.
- The lady-in-waiting’s pillow.
Rule 7: Plural compound nouns
If the compound noun is plural, form the plural first and then use the apostrophe.
- My brothers-in-law’s season tickets
- Our sons-in-law’s new boat
Rule 8: Apostrophe + s with names
Use the apostrophe + s after the second name if two people possess the same item.
Otherwise, use an apostrophe after each name.
- Cesar and Maribel’s home->joint ownership
- Cesar’s and Maribel’s job contracts->separate ownership
Rule 9: Possessive pronouns
Never use an apostrophe with possessive pronouns: his, hers, its, theirs, ours, yours, whose. They already show possession.
- This book is hers, not yours.
Rule 10: Capital letters and numbers
The plurals for capital letters and numbers used as nouns are not formed with apostrophes.
Exception: Use apostrophes with capital letters and numbers to clarify meaning.
- She consulted with three M.D.s.
- He said all of his ABCs before he could walk.
- The show is set in the 1990s. / ( or you could use “the ‘90s”)
- Please dot your i’s.-> You don’t mean the word “is” so we need an apostrophe.
