Question

What is the singular and plural possessive for plague?

I believe it is plague’s.

Answer 1

The singular possessive noun is plague's.
The plural possessive noun is plagues'.

Explanation:

The possessive of most singular nouns is formed by adding an apostrophe s ('s) to the end of the word: plague's
Example: The plague's toll in Europe was great. (the toll of one plague)

There are two accepted ways to make a singular noun ending with s possessive:
-- add an apostrophe s ('s) to the end of the word: sickness's
-- add just an apostrophe (') to the end of the word: sickness'
Both are considered correct for singular nouns that end with s.

The possessive of regular plural nouns ending with an s is formed by just adding an apostrophe (') to the end of the word: plagues'
Example: Nothing could be done to stop the plagues' spread. (the spread of several plagues)

The possessive of irregular plural nouns (plural nouns that don't end with s) is formed the same as singular nouns, by adding an apostrophe s ('s) to the end of the word: children's