Grammar: Apostrophes

A road sign with an unnecessary apostrope s - so business's instead of business

The poor apostrophe (') might be the most abused punctuation mark in the English language. Looking at street signs, advertisements, shop fronts, posters, flyers etc., will indicate that many people have difficulty with proper usage of the apostrophe, so if you struggle with it yourself, don't worry, you're not alone.

The apostrophe has only two uses:

to indicate possession
to indicate the omission of letters or numbers

Here are some examples:

Words have been combined and letters omitted e.g
- wouldn't for "would not"
- I'm for "I am"
- It's for it is
Ownership or belonging to
- Add 's for singular (one)
  - The student's books - the books belonging to the student.
  - Mary's books
- s' for plural (more than one) - "The students' books" - the books belonging to the students.
- If the singular form of the noun ends in s then either form is acceptable
  - James' books
  - James's book
- If the plural form of the noun doesn't end in s then add 's
  - The children's books
- For group/joint possession, add 's to the final member of the group
  - Eoin, Eileen and Kevin's assignment
- For compound words, add 's to the last word
  - Mother-in-law's hat

Don't use an apostrophe for:

a range of years - 1980s not 1980's -"1980's" would mean something belonging to 1980
pronouns that indicate possession his books not his' books

Image: Peter Foster ""Business's"? If your job is to write public notices it is essential you be illiterate.is Public Domain