Only you can make a difference: one person at a time. The apostrophe has been abused horribly, and it’s time to clear a few things up. Apostrophes should be used in the following situations…
1) To show possession
2) To indicate that a letter or a number is missing
3) To indicate the plurals of digits (he got perfect 10’s) BUT NOT years, (the 1920s) or single letters (I got three A’s) but NOT acronyms (we bought 3 CDs) This is less common
4) To clean up words that might look awful when plural (I do’s, yes’s, no’s) This is very uncommon
Remembering #1 is pretty clear-cut. With a few minor exceptions, there is nothing hard about this one, despite general misuse. For example:
Bob’s cat is happy. (There is only one Bob, and he owns a cat.Thus: Bob-apostrophe-s)
The bakers’ feelings were not hurt (notice, the apostrophe is after the ‘s’, so there are many bakers)
He stole the waitress’s tip (no change here – to show possession for a singular noun, use ‘s)
The businesses’ addresses (many businesses, many addresses, there is still no change to the rule)
Mr. Jones’s dog is missing (If you wrote “Mr. Jone’s dog,” you would be changing this man’s name. Also, make sure you follow this rule verbally. If you are talking about Barry Bonds’s homerun record, what you say should sound like “Barry Bond-ziz record”. If you don’t add the extra syllable,it sounds like you are talking about the record belonging to Barry Bond.)*
The Joneses’ picnic table (More than one Jones are several Joneses, right? Still, no change to the rule)
NOTE: Use ‘s at the end of plurals that do not end in s, like the media’s role or the cacti’s home
ALSO: In compound subjects,(e.g. “Doug and Jen”), here’s the rule: If the possessed object belongs to both people, the apostrophe only goes with the last person. For example, if Doug and Jen share a car, it is “Doug and Jen’s car.” If there is a different possessed object owned by each person, the apostrophe goes on each person. For example, if two cars arrived, you would see “Doug’s and Jen’s cars.” Why not say “Doug and Jen’s cars?” That wrongly states that they jointly own several cars. One last point: following the same logic, if you have a possessive adjective as part of the compound subject, follow the same rules. “Doug and my car” belongs to Doug and me, while “Doug’s and my cars” are two different cars –one is his, one is mine.
THE LONE EXCEPTION TO RULE #1: People of worldly importance whose names end in “s” do not have another “s”tacked on (e.g. Dickens’ novel, Columbus’ nose)
Rule #2 is equally easy to keep straight. Here are some examples…
Contractions: Didn’t (did nOt), he’ll (he WIll) might’ve (might HAve)
Poetic abridgements: Usually done to preserve meter, if a poet needed to make “over” fit into a space that required only one syllable, he might use “o’er”. (e.g. ‘tween =between, ne’er = never)
Decades: People often get this one wrong, writing “the fifties” as “the 50’s”. What is missing between the zero and the ‘s’? Nothing. It should be the ‘50s, since the “19” has been chopped off.
Please regard the following rule: APOSTROPHES ARE NEVER USED TO MAKE OBJECTS PLURAL. NEVER …SERIOUSLY.
* = some style guides have started to concede that omitting the final ‘s’ – the one after the apostrophe – on a proper noun that ends in s, like “Jess” “Kansas”or “the Swiss” is acceptable. BHS favors the rule stated here. Two unforgivable mistakes: inconsistency (if you omit the extra s, you have to do so all the time) and pronunciation (Kansas’ is still pronounced “Kansas-izz” when said out loud)
Download this sheet here: Apostrophes