Question

When do I place the apostrophe after the “s,” and when does it go before the “s”? I feel like I once knew the rules, but now I’m in the habit of relying on autocorrect,and my professor marked errors in my paper :-/

Answer

First off, let’s review the two uses of apostrophes:

1. To replace letters in conjunctions: can’t, won’t, couldn’t. (Note that contractions should not be used in most academic writing).
2. For possessives, which show a relationship of ownership: John’s car, the children’s lunches, the employees’ timecards, family members’ ages.

RULES

1. For possessives of singular nouns and plural nouns that do not end in “s,” the apostrophe goes before the “s”: John’s car, the children’s lunches.
2. For possessives of plural nouns ending in “s,” the apostrophe goes after the “s”: employees’ timecards, family members’ ages.

EXCEPTIONS

1. The one possessive that does not need an apostrophe is “its”: The salesperson showed us the phone and its features. (“It’s” is the contraction of “it is.”)
2. There are sometimes exceptions for proper nouns ending in “s”: Names ending with an unpronounced “s” and Greek names ending in “-es” may get just an apostrophe even though they are singular (Camus’ plays, Socrates’ disciples). However, these exceptions may be implemented differently by different style guides or publications.

Need a quick-reference resources for apostrophe rules? This infographic is the best!