Use an apostrophe to show possession: the cat’s toy
Use an apostrophe to show omitted letters in contractions: don’t, it’s, you’re
Use an apostrophe for plural letters, numbers, and symbols when needed: mind your p’s and q’s, the 1990’s
Do not use an apostrophe to make regular plurals: apples, dogs, cars
Use an apostrophe with singular nouns to show ownership: the teacher’s desk
Use an apostrophe with plural nouns ending in s by adding only the apostrophe: the students’ books
Use an apostrophe with plural nouns not ending in s by adding apostrophe s: the children’s game
Use an apostrophe in contractions where letters are omitted: can’t, won’t, I’m
Do not use an apostrophe in possessive pronouns: hers, theirs, its, yours
Place the apostrophe where the omitted letters or ownership belong: who’s, dog’s, girls’