The singular possessive is author's. The plural possessive is authors'.
The plural possessive form is actors' association (the association of actors)
theaters
The performances of the season is the season'sperformances (one season).The performances of the seasons is the seasons'performances (two or more seasons).
athenian theater, medieval theater, Elizabethan theater, and panoramic theater the difference between the four is their architectural design only
Coaster's is singular possessive. The plural is coasters, the plural possessive is coasters'.
The correct form is "its" for the possessive form in the plural. "Its" is used for both the singular and plural possessive forms, without an apostrophe.
The plural is briefs. The plural possessive is briefs'.
The plural is lads. The plural possessive is lads'.
The plural is trollies. The plural possessive is trollies'.
The plural is relatives. The plural possessive is relatives'.
The plural is stations. The plural possessive is stations'.
Museum is singular. Museum's is singular possessive. Museums is plural. Museums' is plural possessive.
The singular possessive form is heart's; the plural possessive form is hearts'.
The plural of rose is roses. The plural possessive is roses'.
The plural form is homes; the plural possessive is homes'.
The singular possessive is biker's; the plural possessive is bikers'.