Five rules for navigating perplexing possessives
Puzzles, math and logic problems supposedly stave off Alzheimer’s. I must be toast since I’m bad at all three. Perhaps there’s hope for me yet since I almost always have to go on a mind-bender to figure out how to handle tricky possessives.
Many writers are confused by the choice between only an apostrophe and an apostrophe, plus an additional “s.” If you can remember some simple rules — or look them up in a grammar manual, as I sometimes have to do — you’ll be in good shape.
1. If a singular noun does not end in “s,” add an apostrophe “s.”
The market’s rally
President Obama’s health-care bill
Tip: For singular nouns ending in “ce,” “x” or “z,” use apostrophe “s.”
The box’s contents
Marx’s theories
Science’s need for researchers
2. If a singular noun ends in “s,” add apostrophe “s” – unless the next word begins with “s.” If the next word begins with “s,” add only an apostrophe.
The hostess’s invitation
The witness’s testimony
The witness’ story
3. If a singular proper noun ends in “s,” add only an apostrophe.
Morris’ memoir
Paris’ cuisine
Dickens’ novels
4. For plural nouns that end in “s,” add only an apostrophe.
The horses’ food
The girls’ toys
States’ rights
5. If a noun is plural in form, but singular in meaning, add only an apostrophe.
Mathematics’ rules
Measles’ effects
Tip: Apply the same rule when a plural word occurs in the formal name of a company.
General Motors’ profits
The United States’ wealth
If you want to get technical about it, you could look up what to do in cases of special expressions, descriptive phrases and names, quasi and double possessives, etc., but you probably don’t use those much in everyday writing. Just keep the above five rules in mind and you’ll be in good shape.