The plural form of state is states.
The plural of "state" is "states".
The plural possessive form is the possessive form (ownership or attribute) of a plural noun. When a plural ends in S, the possessive form adds only an apostrophe. When a plural does not end in S, the possessive form uses apostrophe S. Examples: state - plural states - plural possessive states' (The states' governors met in Miami. - governors of more than one state) child - plural children - plural possessive children's (The children's coats were kept in the closet. - coats of more than one child) mouse - plural mice - plural possessive mice's (The mice's tails were caught in the trap. - tails of all the mice)
"States" can be a noun meaning a condition or situation, but it is not typically used as a possessive form. The possessive form of "states" would be "state's" if referring to something belonging to a state.
The question is a bit confusing. Since there is only one state and one river named Mississippi, I can't think of a use for a plural form of the noun.If, for some reason you would have a use for a plural form, it would be two Mississippis. The plural possessive form would be the two Mississippis' border.
"Mess" is typically used as a singular noun, referring to a disorganized or untidy state. However, it can also be used informally as a plural noun when referring to a group of individuals, as in "These kids are a real mess."
Plural possessive nouns indicate ownership of more than one item by adding an apostrophe after the plural form of the noun. For example, "the dogs' toys" shows that the toys belong to more than one dog.
The plural is heads of state
The plural form of city-state is city-states.
secretaries of state
Secretaries of State
Guilt is an uncountable noun for a state or feeling. It has no singular or plural.
state attornies general
The plural of undersecretary is undersecretaries.
The plural form of candidate is candidates.
The plural form for the noun zoo is zoos. The plural possessive form is zoos'.Example: The zoos' inspections in our state are done on annual basis.
One city-state is a polis. Poleis is plural.
There is no plural form for the noun dismay. Dismay is a state of being, you are either in that state or you are not. When you need to say that a number of people are in the state of dismay, you use the adjective form, the dismayed people, or the verb form, they were dismayed.
Mississippi is singular. Since there is only one state and one river by that name, it would be rare to have need of a plural form.