The apostrophe is used to show ownership. Most of the time, it presents no confusion:

  • Bob’s bassoon
  • The woman’s finger
  • My son’s toys

The tricky part is using an apostrophe when the owner is plural.


1. If the plural noun doesn’t end in -s, add an apostrophe and -s, as shown above. (This is the easy part.)

  • the bacteria’s growth
  • the mice’s hairballs

2. If the plural noun ends in -s, just add an apostrophe.

  • the babies’ bottoms
  • the horses’ hooves
  • the politicians’ promises

3. If the word is a proper noun that ends in -s, add an apostrophe and an -s. (This is the part people get wrong). Use ONLY with proper nouns. All other plurals should follow the rule above.

  • Yeats’s poem
  • Ross’s riddle
  • Chris’s crisis

An alternate way to express the possessive for proper nouns already ending in -s is to simply put the apostrophe at the end of the -s.

  • Yeats’ poem
  • Ross’ riddle
  • Chris’ crisis
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