Use
; Apostrophes are used to indicate possession and in contractions. : Add an "'s" when the noun does not end in an "s" (driver's) or when the noun is singular and ends in an "s" (Lois's). :: However, if the pronunciation of a word would be awkward with the "s" added, it is acceptable not to use the extra "s". : If the noun is plural and ends in "s", you don't need to add an apostrophe (diplomas' instead of diploma's). ; Joint Possession : If there is a compound noun, add the possessive apostrophe to the last noun. :: Example: I went to see Anthony and George's new apartment. (The apartment belongs to both Anthony and George.) : If the compound noun indicates individual possession, add the apostrophe to both nouns. :: Example: Mary's and Brian's sense of style was quite different. (Mary and Brian have individual senses of style.) ; Compound Nouns : If a compound noun uses dashes, place the apostrophe after the last nouns. :: Example: My brother-in-law's house
Common Misuses
* Do not use apostrophes in nouns that are not possessive. Example: Some parent's are more strict than mine. (Apostrophe is not necessary) * Do not use an apostrophe in possessive pronouns such as its, whose, his, hers, ours, yours, and theirs.