The plural form of the noun couch is couches.
The plural possessive form is couches'.
example: All of these couches' prices are too high.
The plural possessive for "couch" is "couches'".
Couches
The singular possessive form of "couch" is "couch's."
The plural is relatives. The plural possessive is relatives'.
The plural is lads. The plural possessive is lads'.
The plural form is Mexicans. The plural possessive is Mexicans'.
The plural form is suffixes. The plural possessive is suffixes'.
The plural of couch is couches.
The plural noun for couch is couches.
The singular possessive form of "couch" is "couch's."
Coaster's is singular possessive. The plural is coasters, the plural possessive is coasters'.
The plural of couch is couches (as with touch and touches).
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.