I'm having a duh moment. If I am writing the sentence ... "Here's a very nice vehicle for sale with x miles that runs excellent with its' strong 3.8 liter engine.." Is there such a word as its'? I'm having a memory block back to 3rd grade. I know it's is either it is or it has, but isn't its already showing posession, and therefore does not need the apostrophe? Help! (Yes, I am selling a car, and I know it's against the rules to post it here, and I'm not trying to circumvent anything. I really do just want grammar help.)
In standard English grammar, the only use for the term "it's" is the contracted form for "it is". The possessive term showing ownership is always "its".
Since you're using it as a pronoun, I think this is relevant (from http://dictionary.reference.com/browse/its) its /ɪts/Pronunciation Key - Show Spelled Pronunciation[its]Pronunciation Key - Show IPA Pronunciation–pronoun the possessive form of it (used as an attributive adjective): The book has lost its jacket. I'm sorry about its being so late. [Origin: 1590–1600; earlier it's, equiv. to it1 + -'s1] —Usage note While it is possible to use its as a predicate adjective (The cat is angry because the bowl you're eating out of is its!) or as a pronoun meaning “that or those belonging to it” (Your notebook pages are torn. Borrow my notebook—its aren't), such use is rare and in most circumstances strained. See also me.
