Rule 1c. Some writers and editors add only an apostrophe to all nouns ending in s. And some add an apostrophe + s to every proper noun, be it Hastings’s or Jones’s.
One method, common in newspapers and magazines, is to add an apostrophe + s (’s) to common nouns ending in s, but only a stand-alone apostrophe to proper nouns ending in s.
An ending used in writing to represent the possessive morpheme after most singular nouns, some plural nouns, especially those not ending in a letter or combination of letters representing an s or z sound, noun phrases, and noun substitutes, as in man's, women's, baby's, James's, witness's, (or witness' ), king of England's, or anyone's. S&W manufactured about a gazillion different handgun models between 1857 and 2005 and will probably add a couple more while I type this sentence. Well, maybe that's a bit of an exaggeration, but they cover 87 pages in the Blue Book and that serial number will have been used on many of them. Search the world's information, including webpages, images, videos and more. Google has many special features to help you find exactly what you're looking for.
Examples:
the class’s hours
Mr. Jones’ golf clubs
the canvas’s size
Texas’ weather
Note: We sometimes hear that an inanimate object cannot possess, e.g., the canvas’s size should be written the size of the canvas. However, this idea is routinely ignored by good writers (the rocket’s red glare).
Care must be taken to place the apostrophe outside the word in question. For instance, if talking about a pen belonging to Mr. Hastings, many people would wrongly write Mr. Hasting’s pen (his name is not Mr. Hasting).
S&p 500 Today
Correct:Mr. Hastings’ pen
S&w M&p 9mm
A widely used technique favored for its simplicity is to write the word as we would speak it. For example, since most people saying 'Mr. Hastings’ pen' would not pronounce an added s, we would write Mr. Hastings’ pen with no added s. But most people would pronounce an added s in 'Jones’s,' so we’d write it as we say it: Mr. Jones’s golf clubs. This method explains the punctuation of for goodness’ sake.