The plural form of the plural noun passengers is passengers'.Example: All of the passengers' luggage has been stowed.
The plural possessive form is passengers'.
The possessive singular noun is explorer's. The possessive plural noun is explorers'.
The possessive form for the noun coyote is coyote's.
The possessive noun for laboratory is laboratory's.
The possessive noun of "preacher" is "preacher's."
The possessive noun of "zoo" is "zoo's."
"He" can function as a possessive pronoun (e.g., "This is his book"), but it is not a possessive noun on its own.
The possessive noun form of "oxygen" is "oxygen's."
The possessive form for the noun coyote is coyote's.
The possessive form is grandson's.
The possessive form is island's.