The word country's is the possessive form of the singular noun country.
Example: That country's flag is green and red.
The plural form of the noun country is countries.
The plural possessive form is countries'.
Example: All of the participating countries' flags weredisplayed.
The word countries is the plural form of the singular noun country.The possessive form of the plural noun is countries'.The singular possessive form is country's.
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
The singular possessive is Martin's.
The singular possessive is fish's.
Grave's is the singular possessive.
The singular possessive is test'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.