Possess is a verb. Its plural form (the one used with plural subjects) is possess, while the form used with singular subjects is possesses.
Examples:
We possess, they possess.
He, she or it possesses.
The noun form of possess is possession, plural possessions.
It is a verb, not a noun, so possess is already the plural form. Possesses is the singular verb form. The verb pluralization rules are opposite the noun pluralization rules that most know.
"He possesses." <-- Singular
"We possess." <-- Plural
Possession would be the noun form, and the plural of possession is possessions.
"This watch is my most prized possession." <-- Singular
"The fire took all of our possessions." <-- Plural
The plural form of quiz is quizzes.
The plural form for the noun index is indexes.
Plural of zero is zeroes.
Chests is the plural of chest.
The plural of colt is colts
Italy does not have a plural form.
The plural form of him, her, or it is them. (objective pronouns)
The plural form is spelt : subpoenas.
The plural form of beauty is beauties.
The plural form of radius is radii.
The plural form of quiz is quizzes.
The possessive form of the plural noun traditions is traditions'.Example: These traditions' origins are centuries old.
Trout is plural
The plural form of the noun 'sea' is seas.
The plural form for the noun coach is coaches.
The plural form for the noun index is indexes.
The plural form of "atlas" is "atlases."