I have never really found a default method I like for dealing with languages. There seem to be so many issues surrounding it.
My preference is to have a default language for the site and language alternatives I write to a cookie and read that to decide which language content to deliver. Thus no change to url formats at all, and any bits of text I have missed are delivered in English, without any errors appearing. However I am not sure this is best practice for SEO reasons.
However, you can add as many params as you want to the URL, and any not collected in the controller are ignored.
I tried once and quite liked having non-default languages as sub domains, such as fr.mydomain.co.uk or thai.mydomain.co.uk which has worked well for me in the past, but maintenance was a pain and I don't think I would do that again.
However, I have not tried this, but I think it would be ideal to have different languages on different domains, so mydomain.co.uk in English, mydomain.fr in French etc etc. I am going to try that next time it arises although I can see some issues coming from it, but as I said, have not tried it yet.
I am not sure if that helps at all but I hope it does.
Paul.
