Like so: "The platypus's natural environment is a pleasant one".
The singular possessive form is heart's; the plural possessive form is hearts'.
That would be the plural using Greek rules: both platypus and octopus are from Greek, and do not (as is commonly assumed) use the Latin plurals platypi and octopi.The correct English plural is either platypuses or the same word platypus (used as a group noun, like sheep or trout).
The possessive form is subsidiary's.
The possessive form of "synopsis" is "synopsis's" or "synopsis'."
No, it is singular, the possessive form of it is its. The plural form of it is they or them, and the possessive form is their.To answer the question directly: there is no such word as ITS'.
The singular possessive is Richard's; the plural possessive is Richards'.
The possessive form is battleship's.
Bicyclist's is the possessive form.
The possessive form is librarian's.
The possessive form of "he" is "his": He did his homework after dinner.
The possessive form is posse's.
The possessive form for "lawyer" is "lawyer's."