Aerial view of campus with Williamsport, the Susquehanna River and Bald Eagle Mountain as a backdrop

Apostrophes

To indicate possession

  1. To form the possessive of a singular noun, add an apostrophe and an s.
    • zebra's stripes
    • dean's list
    • crocodile's teeth
  2. To form the possessive of a plural noun ending in s, add only an apostrophe.
    • dragons' victims
    • women's studies
  3. To form the possessive of a singular proper noun (even if it ends in s), add 's.
    • Jesus's words
  4. Do NOT use an apostrophe to form the plural of an abbreviation or a number. Instead, simply add s.
    • Ph.D.s
    • 1990s
    • VCRs

Contractions

  • Apostrophes may be used for contractions but they should be avoided in formal writing.