The plural form of the noun Copernicus is Copernicuses.
The plural possessive form is Copernicuses'.
Example: The Copernicuses' home was in Torun, a city of the Polish kingdom.
The single possessive of "Copernicus" is "Copernicus's." This indicates that something belongs to Copernicus, such as "Copernicus's theory." In some style guides, you might see it simply as "Copernicus'" if the name ends in "s," but "Copernicus's" is generally accepted.
The plural possessive is experiments'.
The plural possessive form of "faculty" is "faculties'."
The plural is Ph.Ds or PhDs (people) and the plural possessive is PhDs'.(the abbreviation with a period or periods is normally used after a name)
The plural possessive form of "experiments" is "experiments'".
The single possessive of "Copernicus" is "Copernicus's." This indicates that something belongs to Copernicus, such as "Copernicus's theory." In some style guides, you might see it simply as "Copernicus'" if the name ends in "s," but "Copernicus's" is generally accepted.
Singular possessive: secretary's Plural: secretaries Plural possessive: secretaries'
The plural is relatives. The plural possessive is relatives'.
The plural is lads. The plural possessive is lads'.
The plural form is echoes. The plural possessive is echoes'.
The plural form is suffixes. The plural possessive is suffixes'.
The plural form is Mexicans. The plural possessive is Mexicans'.
The plural form is stepsisters. The plural possessive is stepsisters'.
The plural form is inches. The plural possessive is inches'.
The plural possessive of "Father" is, "Fathers"
The plural possessive of bandit is bandits'.
Studies' is the plural possessive of study.