Use an apostrophe to indicate:

  • The possessive case of singular and plural nouns, indefinite pronouns, and proper nouns:
 my sister's sonsomebody's lunch
 my two sisters' sonsCharles's house
 the children's toysthe Rosses' friends
  • The plural of letters, numbers, symbols, and words used as such:
 too many thus's ten 5's in a row
 spelled with two e'sdelete some &'s
  • Missing letters in contractions and missing numbers in dates:
 I'm (I am) class of '95
 ma'am (madam)winter of '97–'98

See also: Apostrophes

Brackets & ParenthesesPunctuationQuotation Marks