Possessive apostrophes are apostrophes (’) used with the letters at the end of a noun to show ownership over or a close connection with another noun. For example, if you were talking about the tail of your cat, you can add a possessive apostrophe and an s to show which noun is the owner.
It sleeps wherever it’s legs give out. His little kitty knees must be powder
Yeah. Can’t be healthy, his head to body ratio is ridiculous.
It’s very unhealthy, and its owners should be ashamed of themselves
It’s not just “not healthy.” It’s fuckin animal abuse.
its*
(It’s is it is)
“Its knees work hard because it’s severely overweight.”
It’s*
noun, possessive
The cat has knees. It’s knees are powder.
From your own source:
“When should you not use a possessive apostrophe? Do not use possessive apostrophes with pronouns, which have their own unique possessive forms.”
You wouldn’t use he’s or she’s or they’s for possession. It goes: his, hers, theirs, its. The cat’s knees = its knees.