I know top domains, sub domains or folders is preferable when making a site for multiple languages. I'm thinking about some examples here on the forum using static folders but a problem as I see it is that the collection item can't be under that folder. So the url structure is not consistent.
Is it maybe a good idea just to make a collection for each language instead? So if you have a collection named news for english, domain.com/news/ , you make another for your other language, domain.com/nyheter/. And the same for any other collection that needs template pages. Little hard to maintain of course but the site owner gets good control over the SEO settings for each item.
Question for SEO experts, could this be a good solution? For the user you have a good set up where he knows where he is and can change language any time of course.