The plural form of the compound noun brother-in-law is brothers-in-law.
The plural possessive form is brothers-in-law's.
example: Both of my brothers-in-laws birthdays are on the same day.
Brothers-in-law's
The plural form for the noun citizen is citizens.The plural possessive form is citizens'.Example: The bridge was funded by hundreds of citizens' contributions.
The plural of comrade is comrades.
The plural of survey is surveys.
The possessive form of the proper noun Ms. Smith is Ms. Smith's.example: Ms. Smith's office is on the second floor.
The plural of sit-in is sit-ins.
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 of senior is seniors. The plural possessive of seniors is seniors'
The singular possessive of "ant" is "ant's" and the plural possessive is "ants'".
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 plural possessive form of "chorus" is "choruses'."
The singular possessive form is heart's; the plural possessive form is hearts'.