The singular possessive for "criterion" is "criterion's."
Criteria is plural. Criterion is singular. The criteria to pass a maths exam is being able to add up and subtract. The criterion of passing an addition exam is being able to add up.
The singular possessive form of "test" is "test's".
The singular possessive pronouns are "my," "mine," "your," "yours," "his," "her," and "its."
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 form of "classmate" is "classmate's."
Taco's is the singular possessive.
The singular possessive of dish is dish's
The singular possessive is Martin's.
Buzz's is the singular possessive.
The singular possessive is fish's.