Both the singular and the plural is aircraft.The plural possessive form is aircraft's.Example: All of the aircraft's inspections have been completed.
The noun 'aircraft' is an uncountable noun. The singular and the plural possessive form is aircraft's.EXAMPLESOne aircraft's owner has not paid the airport fee. (singular)All of these aircraft's owners are delinquent in their fees. (plural)
The singular possessive form is week's.
The singular possessive form of "classmate" is "classmate's."
The possessive form is Amos's.
The singular possessive form of "gypsy" is "gypsy's."
The singular possessive form of "countries" is "country's".
The singular possessive form of county is county's.
The singular form is goose; the singular possessive form is goose's.The plural form is geese; the plural possessive form is geese's.
singular possessive: boy'splural possessive: boys'
The singular possessive form is speculum's.
The singular possessive form is contralto's.