Prompted by comments against this question, I'd like some help figuring out why some people (myself included) prefer yours over the apparently more logical/grammatically consistent your in this kind of sentence...
Yours and my native languages have co-existed for hundreds of years.
Google Books has Your:Yours ratios for languages:2:2, parents:9:10, houses:4:2. That's a very small sample size, admittedly - but even without anything like that, I know my own usage. So I'm not really interested in being told which is correct, except insofar as this has a bearing on my question itself - why do some people, (including some "careful speakers", which I don't necessarily claim to be) use the apparently incorrect form?
EDIT: It may be important to note (as @Gnawme guessed without it being explicitly stated in the first version of this question) that I personally would use singular language in the above. It was just too difficult to search Google Books for that particular distinction, so I said nothing about it.