Their practice is that any time a words ends in "s," you put an apostrophe after the "s" to make it possessive.
The Associated Press Stylebook says the correct way to write the possessive case of Chris is Chris', not Chris's. Other style guides, including the Chicago Manual of Style, say Chris's is correct. If there isn't a specific guidebook you need to follow, you can use either Chris' or Chris's.
Most experts and guides say you should add an apostrophe and an S to both proper and common nouns to make them possessive even when they end in S. So, using the examples above, it would be: Chris's car. the crocus's petals.
If you're going with The Associated Press Stylebook, James' is the correct way of writing James in the possessive form. But, for all other style guides, James's is the way to go.
The apostrophe has three uses: 1) to form possessive nouns; 2) to show the omission of letters; and 3) to indicate plurals of letters, numbers, and symbols. Do not use apostrophes to form possessive pronouns (i.e. his/her computer) or noun plurals that are not possessives.
How to pluralize words ending in S. For the majority of words ending in S, you just add an -es to the end. “Walrus” becomes “walruses,” “bus” becomes “buses,” “class” becomes “classes.” Not too bad.
Second, a name ending in s takes only an apostrophe if the possessive form is not pronounced with an extra s. Hence: Socrates' philosophy. Saint Saens' music.
“I visited Thomas's house” and “I visited Thomas' house” are both valid style choices. But the former is more popular in professional publishing. So a safe solution is to treat singular nouns ending in S the same way you treat singulars nouns not ending in S: Form the possessive with an apostrophe and an S.
If the singular noun ends in “S”, it is usually recommended to add an apostrophe + “S,” whether it's a common or proper noun.
The possessive of a singular noun is formed by adding 's (whatever the final consonant). Note that some consider Jesus to be an exception to this rule and insist that its possessive be written Jesus'; other exceptions may include other ancient proper names.
Turns out, The AP Stylebook has always called for the opposite: only an apostrophe after a proper name that ends in the letter S. So not only would you write “Moses' wife,” “Achilles' heel,” and “Jesus' disciples,” you would also write “Chris' birthday” and “Jane Strauss' house.”
The plural of Jones is Joneses, ‐es being added as an indicator of the plurality of a word of which the singular form ends in s, as in dresses or messes. The apposition of the much misused apostrophe to the word Jones does not pluralize it.
The possessive
Quick Use: Use an apostrophe + s for singular nouns (sea, sky), common nouns ending with s (tigress, mistress), and irregular plural nouns (women, children). Use only the apostrophe for proper nouns ending with s (Tess, Jesus, Texas) and regular plural nouns (cars, protestors).
Rule: To form the plural of a last name that ends with an s, add an es. To form the possessive of the plural, add an apostrophe. The Dennises are a nice family.
In English, the possessive of every singular noun--even singular nouns that end in "s"--is formed by "apostrophe s" with one curious exception (which I'll get to in a moment). Thus "Joe's bike" and "Jess's bike" are both correct but "Jess' bike" is incorrect.
When making your last name plural, you don't need to add an apostrophe! The apostrophe makes the name possessive. The last letter of your last name will determine if you add an “-s” or an “-es”. If your last name ends in -s, -z, -ch, -sh, or -x, you add -es to your last name to make it plural.
An apostrophe is a small punctuation mark ( ' ) placed after a noun to show that the noun owns something. The apostrophe will always be placed either before or after an s at the end of the noun owner. Always the noun owner will be followed (usually immediately) by the thing it owns.
First, form your plural: You're visiting the Rosses. Then make it possessive: You're going to the Rosses' house. Remember, because this is plural, there's no dispute on how to make it possessive. Use just an apostrophe.
The Associated Press Stylebook recommends just an apostrophe: It's Tennessee Williams' best play. But most other authorities endorse 's: Williams's. Williams's means “belonging to Williams.” It is not the plural form of Williams. People's names become plural the way most other words do.
According to Grammarbook.com, the nerds of the world will argue heatedly on the subject for eternity, but the most roundly accepted rule is to include the apostrophe, along with an extra “S.” (Davis's rather than Davis').
If the name ends in s, z, ch, or sh, you need to add es. That means the Davis family becomes the Davises, the French family becomes the Frenches, the Hernandez family becomes the Hernandezes, and the Glaves family becomes the Glaveses. If the name ends in x, also add es—unless the x is silent.
To show individual ownership, each noun/name has an apostrophe s. EXAMPLES: Joint: Mary, Beth, Phil, and Bill's house. Individual: Mary's, Beth's, Phil's, and Bill's houses.
If you can remember one rule about apostrophes, remember: 'Possession not plural'. Make this your mantra for apostrophes and it will make it much easier to remember when to use one and when not to.
Use an apostrophe when showing possession
If the plural of the word is formed without adding an "s" (for example, children), add apostrophe "s" ('s) as you would to the singular form. Examples: one table's leg or several tables' legs. one student's name or several students' names.