Singular possessive:only one Jack owns the canary.
Plural
The possessive noun for the singular word canary is canary's, e.g. "The canary's seed dish".The possessive plural form for many canaries would be canaries', e.g. "The canaries' seed dishes".
The form "Jacks" is the plural form of the proper noun "Jack".The possessive form of the singular noun "Jack" is Jack's.Examples:There are two Jacks in my class. (plural)Jack's decision pleased his parents. (possessive)
The singular possessive form is canary's.
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 stations. The plural possessive is stations'.
The plural is relatives. The plural possessive is relatives'.
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'.