Apostrophes

Use an apostrophe

• To form the possessive case of nouns. For singular nouns, add an apostrophe and an s, even if the noun ends in s, x, or z. To form the possessive of plural nouns that end in s, add only an apostrophe.
  Examples
  insider's guide
  the box's contents
  the CSS's flexibility
  Berlioz's opera
  an OEM's product
  users' passwords
  the Joneses' computer

• To indicate a missing letter in a contraction.
  Examples
  can't
  don't
  it's

Don’t use an apostrophe

• For the possessive form of it.
  Example
  Replace a formula with its calculated value.

• With a possessive pronoun.
  Example
  The choice is yours.

• To form the plural of a singular noun.
  Example
  Play your favorite games on all your devices.

Note Don't use the possessive form of Microsoft trademarks and product, service, or feature names.