The word community is singular; the plural form is communities.
The plural form of the noun 'community' is communities.
Communities is already in its plural form. The singular form is community.
The plural form for the noun community is communities.The plural possessive form is communities'.Example: Many communities' resources were pooled to help with the flood damage.
The plural form of the compound noun notary public is notaries public.The plural possessive form is notaries public's.
There is no plural. The word 'public' is a mass noun.
The plural possessive form for comity (one m) is comities'. If you meant the noun committee, the plural possessive form is committees'. If you meant the noun community, the plural possessive form is communities'.
The plural form of the noun church is churches.The plural possessive form is churches'.Example: Our community churches' contributions made the project possible.
The noun public (the public, the citizenry) is a collective noun, and can use either the singular or plural form of a verb depending on its use.
If you meant to say community, then it is communities.
Notaries public
The plural form of the noun wife is wives.Example: Our wives work at the community garden in their free time.