1. Apostrophe Usage: To show the omission of letters
Examples: It’s = it is; who’s = who is
2. To indicate certain plurals
Examples: “Mind your p’s and q’s”;
I want all A’s on my report card this year!
3. To form possessive nouns
Examples: Three days’ pay; Chris’s shoe; children’s library

2. Common Errors! It’s = it is Ex: It’s cold outside (it is cold outside)
Its fur was soft (its is a possessive pronoun)
Who’s = who is
Ex: Who’s is coming for dinner (who is coming for dinner)
Whose shoe is this?
You don’t need apostrophes to show possession with buildings, objects, or furniture.
Ex: The car door; the chair leg
You don’t need an apostrophe with noun plurals
Ex: homes, hours, days, dogs
No apostrophe: The 1980s; 1600s; ‘80s
Merry Christmas! Love, The Tomsons
Irregular plural possessives (not ending in s)
Ex: Children’s library; geese’s poop; women’s restroom

3. Personal Pronouns vs. Indefinite Pronouns
Apostrophes should not be used with possessive pronouns because possessive pronouns already show possession—they don't need an apostrophe. His, her, its, my, yours, ours are all possessive pronouns. However, indefinite pronouns--one, anyone, somebody, and anybody--can be made possessive. INCORRECT: his' book CORRECT: his book CORRECT: one's book CORRECT: anybody's book INCORRECT: that books is her’s CORRECT: that book is hers