The word "citys" is an incorrect spelling for the plural noun city. To show possession, an apostrophe is used. The correct forms are:
Singular: city
Singular possessive: city's
Plural: cities
Plural possessive: cities'
The word city's is the singular possessive noun.
The plural form of the noun city is cities. The plural possessive form is cities'.
example: The cities' mayors agreed on a date for the celebration.
Museum is singular. Museum's is singular possessive. Museums is plural. Museums' is plural possessive.
The singular possessive of "ant" is "ant's" and the plural possessive is "ants'".
The singular possessive is biker's; the plural possessive is bikers'.
The word sisters' is plural possessive. The singular is sister, singular possessive is sister's; the plural is sisters, the plural possessive is sisters'.
The singular possessive is army's.The plural possessive is armies'.
The singular possessive is avocado's; the plural possessive is avocados'.
Niece's is a singular possessive noun. niece - singular nieces - plural niece's - singular possessive nieces' - plural possessive
Women's is a plural possessive. The singular possessive is woman's
The singular possessive form is heart's; the plural possessive form is hearts'.
The singular possessive form is headdress's. The plural possessive form is headdresses'.
The singular possessive is author's. The plural possessive is authors'.
The singular possessive is author's. The plural possessive is authors'.