Use an apostrophe to indicate ownership by a proper noun. An apostrophe with an “s” after a proper noun indicates that the person, place or thing owns whatever noun follows his or her name. For example, “Mary’s lemons.” We know the lemons belong to Mary because of the ‘s. Other examples include “China’s foreign policy” and “the orchestra’s conductor.”
- Ownership with certain proper nouns can be tricky. “Sunday’s football game” is not technically correct grammar (because it’s incapable of ownership) but it’s perfectly acceptable to say and write. “A hard day’s work” is likewise perfectly correct, even though the day is incapable of ownership.
Be consistent when you use apostrophes after words that end in “s.“ When someone’s name ends with an “s,” it is acceptable to use an apostrophe without an “s” to show ownership, but linguists with the Chicago Manual of Style, along with others, prefer to add an “s” after the apostrophe.
- Note the difference in usage:
- Acceptable: Jones’ house; Francis’ window; Enders’ family.
- Preferred: Jones’s house; Francis’s window; Enders’s family.
- Whichever style you prefer using, be consistent with it. It doesn’t really matter which policy you adopt, as long as you adopt it consistently.
Don’t use an apostrophe to indicate ownership when using “it”. “China’s foreign policy” is correct, but say your reader already knows you’re talking about China, and you start referring to the country as “it.” If you were to reference something China owned in this way, you’d say “its foreign policy.”
- The reason for this is to avoid confusion between “its” used for possession and “it’s” used as a contraction of “it is.” If you’re not sure whether to use an apostrophe or not, try saying the sentence with “it is” or “it has.” If it doesn’t make sense (the way that “it is foreign policy” cannot substitute for “China’s foreign policy”), then drop the apostrophe.
Use apostrophes to indicate ownership by a plural noun. One common trip-up on apostrophe usage for a plural group occurs when people want to discuss what a family owns. For instance, say the Smart family lives across the street from you and owns a boat. The boat is “the Smarts’ boat,” not “the Smart’s boat.” Because you are talking about all of the members of the Smart family, you would start with “Smarts.” Because all the Smarts (presumably) own the boat, you add the apostrophe after the “s.”
- If the family’s last name ends in “s,” make it plural before adding an apostrophe. For instance, if you wanted to discuss the Williams family, they would become “the Williamses” in a plural sense. If you wanted to reference their dog, you’d say “the Williamses’ dog.” If the last name seems awkward to say that way, sidestep the issue by saying “the Williams family” and “the Williams family’s dog.”
- If you’re listing who owns an object, know where to put the apostrophe. For instance, if both John and Mary own a cat, you would write “John and Mary’s cat” — not “John’s and Mary’s cat.” “John and Mary” is a cohesive noun phrase, and therefore only needs one apostrophe.