The possessive form for the singular, compound noun Smith and Smith is Smith and Smiths'.
example: You'll find Smith and Smith's office on the second floor.
The singular possessive form for Smith is Smith's.
The possessive form of the singular noun smith is smith's.example: I bought this at a goldsmith's shop at the mall.
Quantum is singular, not singular possessive. The singular possessive form is quantum's.
The singular possessive of "ant" is "ant's" and the plural possessive is "ants'".
Museum is singular. Museum's is singular possessive. Museums is plural. Museums' is plural possessive.
The singular possessive pronouns are "my," "mine," "your," "yours," "his," "her," and "its."
The singular possessive of dish is dish's
The singular possessive is Martin's.
The singular possessive is fish's.
Grave's is the singular possessive.
The singular possessive form of "test" is "test's".
Buzz's is the singular possessive.
The singular possessive is biker's; the plural possessive is bikers'.