The plural form of the proper noun Morris is Morrises.
The plural possessive form is Morrises'.
example: The Morrises' children are twins.
There are two accepted forms for possessive singular nouns ending in s:
Add an apostrophe (') after the existing s at the end of the word: Morris'
Add an apostrophe s ('s) after the existing s at the end of the word: Morris's
EXAMPLES
Mr. Morris' office is on the third floor.
Mr. Morris's office is on the third floor.
Note: The -s's is the most commonly used form, but if you are a student, use the form that is preferred by your teacher.
The plural form of the proper noun Morris is Morrises.
The plural possessive form is Morrises'.
example: The Morrises' children are twins.
Quantum is singular, not singular possessive. The singular possessive form is quantum's.
Museum is singular. Museum's is singular possessive. Museums is plural. Museums' is plural possessive.
The singular possessive pronouns are mine, yours, his, hers, and its. The singular possessive adjectives are my, your, his, her, and its.
The singular possessive of dish is dish's
Grave's is the singular possessive.
The singular possessive is test's.
The singular possessive is Martin's.
The singular possessive is fish's.
Buzz's is the singular possessive.
The singular possessive is biker's; the plural possessive is bikers'.
The singular possessive of criteria is criteria's.
There's no such thing as a singular possessive verb. Chris's is a singular possessive noun.