Can anybody help me with singular and plural possessives? Here are the nouns I'm having trouble with:

DONKEY
Singular Possessive __
Plural Possessive
_____

JONES
Singular Possessive __
Plural Possessive
___

PEREZ
Singular Possessive __
Plural Possessive
___

EMPLOYEE
Singular Possessive __
Plural Possessive
___

BUFFALO
Singular Possessive __
Plural Possessive
___