Here are useful rules for the apostrophe. Learn them well, and use them in your writing.
Add an apostrophe and an s to form the possessive of a singular noun.
Joe + ’s = Joe’s car
day + ’s = day’s effort
flag + ’s = flag’s colors
glass + ’s = glass’s cost
Note: If a plural noun ends in s, just add an apostrophe.
cars + ’ = cars’ interiors
televisions + ’ = televisions’ locations
Note: If a plural noun does not end in s, add ’s to the word.
mice + ’s = mice’s home
women + ’s = women’s department
Note: If a name of two or more syllables ends in an eez sound, the possessive is formed
without an additional s.
the tales of Ulysses = Ulysses’ tales
the speeches of Orestes = Orestes’ speeches
organization, add ’s to the last word of the name.
Jackson and Meyer’s law firm