This article is an extension of the client side language selection choices support wiki article here. So read that before you continue on here to get an understanding of how to change language selection on the client side.

The language choice link method explained above dictates that you have url's to change languages that look like this:

www.example.com/index.php?set_language_cookie=29

You may want to shorten that a little bit to something like this:

www.example.com/en

If you use the SEO url rewrite addon explained here and here then you can manually add lines to your .htaccess file (where you other SEO rewrite rules are) to make your language selection links look something like the second url above. In the above example the language id is "29" and the language is English. So you would add something like this to your .htaccess file:

RewriteRule ^en$ index.php?set_language_cookie=29 [QSA,L]

Before the following in that file:

#-end SEO addon-on 

From then on you can use a url like:

www.example.com/en

To allow your clients to switch to the language with the id of "29". For more on deciphering the language id look to the link at the top of this article.

Note this link is ONLY for language selection. It cannot be combined with other SEO rewritten urls.