Conquering the Apostrophe

By Gary Blake | July 28, 2017

After the comma, the second most difficult punctuation mark to master is the apostrophe.

Apostrophes are troublesome because there is no universal agreement about the rule that states that single nouns, including those ending in “s”, add ” ‘s.” There is a widespread mix-up between the use of an apostrophe used to show possession and one to show plural. Finally, people struggle with forming plurals of hyphenated expressions.

To form the POSSESSIVE of:
  1. SINGLE NOUNS, including those ending in “s,” add ” ‘s.” [Includes nouns ending in -se, -z, -ze or -ce].
  2. PLURAL NOUNS ending in “s,” add only the apostrophe.
  3. PLURAL NOUNS not ending in “s,” add “s.”
  4. PERSONAL PRONOUNS in the possessive case, don’t add the apostrophe (.e.g., “I believe the book is hers.” “I thought that theirs was optional.”
  5. INDEFINITE PRONOUNS, add an “s.” (e.g., She finds nobody’s work satisfying.)
  6. HYPHENATED WORDS, including names of organizations or words showing joint possession, add “s” to the last word that’s possessive in form.
    (e.g., Fred and Ethel’s cat, Ingersoll-Rand’s machinery)
  1. To form the PLURAL of letters, numbers and signs, use an apostrophe.(e.g., Mississippi has four “s’s.” “Instead of a “3” and an “8”, he had written two “3’s.”)
  2. To form the PLURAL of acronyms and decades, add “s” only.(e.g., 1990s, HMOs, CEOs, CPAs).
  3. To form a CONTRACTION, use an apostrophe where letters have been omitted in a word. (e.g., I don’t know. We’ll be there. bucket o’ chicken wings).
  4. To form a PLURAL of hyphenated expressions, make the first word plural.(e.g., mothers-in-law, commanders-in-chief)

Now, there are nuances (e.g., its and it’s as well as exceptions to the “single nouns ending in “s” add ” ‘s” rule” that space prevents me from adding. However, I want all of my readers to have complete information. So, I will send my two-color 8 1/2″ X 11″ poster, THE APOSTROPHE, to any of you who request one. Just send your name, title, company and address to me at, and I will send you a poster – free.

image of Gary Blake

About Gary Blake

Gary Blake is director of The Communication Workshop, offering claims writing webinars and seminars to claims professionals throughout the US, Bermuda, Canada, and the UK. Blake is the author of The Elements of Business Writing (Pearson Education), used at more than 100 insurance companies. He has written about claims writing for a number of industry publications. His e-mail is More from Gary Blake

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