The singular form of the plural noun players is player.
The singular possessive for is player's.
example: The player's shoestring came loose and caused him to trip.
The singular form of the plural noun players is player.The singular possessive form is player's.Example: The player's uniform was covered in mud.
The plural form for the noun play is plays; for example: We attended two plays this weekend. Some good plays put us in the lead. The word play is also a verb; verbs do not have singular and plural forms.
The possessive form is Amos'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.
Quantum is singular, not singular possessive. The singular possessive form is quantum's.
The singular possessive form is speculum's.
The singular possessive form is frontiersman's.
The singular possessive form is aircraft's.
The singular possessive form is week's.
The singular possessive form is contralto's.
The singular possessive form is herd's.
The singular possessive form is heart's; the plural possessive form is hearts'.