Just a nitpick, the word it's does not imply possession, you are looking for 'its'. If you cannot substitute your usage of it's with 'it is' then it is the wrong one to use.
Even trying to query Google for the correct rules for it's/its doesn't turn up clear, concise information as you've achieved here in two sentences. Tragically, it's another case of SEO'd to death.
Just remember this[0] and you should be set:
It's is not, it isn't ain't, and it's it's, not its,
if you mean it is.
If you don't, it's its. Then too, it's hers. It isn't
her's. It isn't our's either. It's ours, and likewise
yours and theirs.
[0] http://www.anvari.org/fortune/Miscellaneous_Collections/3944...
Use a dictionary or simply "define:"
He --> his
She --> her
They --> their
We --> our
I --> my
You --> your
It --> its
(Since someone will probably point this out, this is only true of the common pronouns. There are unusual pronouns that have apostrophes in their plurals. Eg: one --> one's. But nevertheless, the rule worked for me.)
Oh wow. So, is this a common thing? When I type without thinking about it too much, and with my typing not being able to keep up with my brain, I tend to make those errors a lot. But I thought it was just me being dumb and not some general thing that happens to people.
I also sometimes put in an entirely incorrect word that is vaguely like the one I intended, with amalgamated hints of a neighbouring word, usually the one after. My brain just melds them together. Sometimes I read what I write and wonder how on Earth I can be such an idiot. Blessed are those times I catch such fuckwittery before posting.
- ed
the its/it's one is really annoying though, because of course I KNOW which is correct, but sometimes my finger just slips and sneaks in that apostrophe.
And yeah, I sometimes created melded words as well. I wonder if there’s a name for our issue.
Eventually, the form become generalized across all nouns, with -es being applied to any noun to indicate possession. In most cases, the e is silent, and typographers began to either omit it (e.g. "whos") or, eventually, replaced it with an apostrophe, as the French did. And I suppose "whose" gained an e to indicate the "long vowel".
So we've ended up in a situation where we've basically lost noun declension and just attach suffixes to indicate plurality and possession (s and 's), but our pronouns have inherited their old declensions, without the -es/-'s suffix attached.
Granted, "its" is itself a semi-recent invention, as OE and middle english used "his" for both masculine and neuter third person singular genitive pronouns.