https://www.youtube.com/watch?v=6BsbzajflC8
AT 0:15 She said "John and I's house in San Diego" For some reason, I think that's grammatically incorrect, to say the least
What do you all think? Obviously, the best option would be "our house" but if I want to explore other options as well I think I would be going out on a limb by suggesting the following "A tour of My and John's house in San Diego" but it sounds less horrible than the other one. Thanks.
You're right, "John and I's house" is completely incorrect. Most people would say "me and John's house", but that is still technically incorrect (but not many people would be so annoying as to correct you if you say that in casual conversation).
The funny thing is, what she did is called "hypercorrection". Meaning she tried so hard to avoid making the mistake of saying "me and John's house" that she made an even bigger mistake.
A better way to say it would be "mine and John's house". I'm not sure if it's 100% grammatically correct, but I am sure that no one would correct you if you said it that way ;)
I THINK (but I'm not sure) that the 100% gramatically correct way to say it would be "John's and my house". Because apparently the trick is to take the other person out of the sentence and see if it still makes sense:
"I's house" - Very wrong
"Me house" - wrong
"Mine house" - still wrong
"My house" - correct
But, I don't think anyone would actually say it that way, even if it's grammatically correct. People would say either "me and John's" or "mine and John's". But don't worry too much about it. As long as your're not saying "[Name] and I's", then it's not a big deal. (Not in casual conversation at least. If you were writing an essay for University or a job application then maybe).