Apostrophes are used to show possession (e.g., dog's dinner), in time expressions (e.g., 2 years' pay), in contractions (e.g., isn't) and, on rare occasions, to show plurals (Z's and 2's).

Apostrophes are tricky but can be mastered. Use them for contractions (can’t), to show possession (dog’s), and to make something easier to read (dot your i’s). Don’t use apostrophes to make a word plural, or with possessive pronouns (yours, its).