Is it Morris or Morris's?
When two or more people own something, you only put the possessive on the last noun. Innocent: Jenna and Morris's dogs were friendly. When Jenna owns her dogs separately from Morris, use the possessive on both nouns. Innocent: Jenna's and Morris's dogs were friendly.
Names are proper nouns, which become plurals the same way that other nouns do: add the letter -s for most names (“the Johnsons,” “the Websters”) or add -es if the name ends in s or z (“the Joneses,” “the Martinezes”).
Don't use an apostrophe to make your last name plural. Apostrophes can be used to show possession—à la the Smithsʼ house or Tim Johnsonʼs pad— but they don't indicate there's more than one person in your family.
...
With names, apostrophes are for possessives.
- The Joneses' dinner was a success.
- The Foxes' house was beautiful.
- The Alvarezes' grandmother was delighted.
- The Churches' singing was heavenly.
- The Ashes' train derailed in the mountains.
Plural Last Name Examples:
Add es to your last name. Examples: If your last name is Jones, you will change it to Joneses. If your last name is Davis, you will change is to Davises.
If a proper name ends with an s, you can add just the apostrophe or an apostrophe and an s. See the examples below for an illustration of this type of possessive noun. You're sitting in Chris' chair. You're sitting in Chris's chair.
“Morris.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/morris.
The rules for pluralization are simple: Use an -s if your name ends with a vowel or a voiced consonant.
For proper names like James, AP says, add an apostrophe only: He borrowed James' car. For generics like boss, add an apostrophe plus S: He borrowed the boss's car. But there's an exception: When the word that follows begins with an S, use an apostrophe only. Hence: the boss' sister.
Jones = Mr. Jones's. Some people favor adding only an apostrophe to a singular noun ending in s, but if you follow the rule, you can't be wrong. If a plural noun does not end in an s, you must make it possessive by adding an apostrophe and an s: women's; children's.
Is it Williams or Williams's?
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.
To form the possessive of a singular noun that ends in an “s” sound, be guided by the way you pronounce the word: (a) if a new syllable is formed in the pronunciation of the possessive, add an apostrophe plus “s,” e.g., Mr. Morris's eyeglasses; Miss Knox's hairdo; Mrs. Lopez's term paper…
That's because the apostrophe before the “s” indicates ownership or possession when that's not the sign's intent. All you need is an “s” at the end of the name (Smiths, Johnsons). If you have trouble remembering whether the apostrophe is necessary, think of your message.
Normally, an apostrophe and then an "s" is used to show ownership. For example, my name as a possessive noun is Parzival's. When the noun ends in s, we put the apostrophe behind the s but don't add another one. So for Francis it's Francis' and not Francis's.
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.