Same question for different locales

Hello,

I would like to show the same question (ie: post) for different locales.

So, for a certain question (eg: post id 20), I want to display that question but display the header, footer and standard text (eg: “your answer”) in the user’s language.

I was thinking of setting a cookie.

Which php page is a post displayed on, so that I can manipulate the header and footer according to the cookie?

Also, I use Polylang and it gets the language from the url.
How can I override this so that, when showing a question, certain text (eg: “your answer”, “edit”, “comment”) on the page will be displayed according to the language that I set with a cookie?

Thanks, I hope I was clear…