My readers come from more than 20 countries around the world, they say in different languages, taking into account this problem, so I have recently examined the WordPress Multi Languages Plugins, hope to some of my thoughts to others.
1. Transposh Translation Filter
Transposh aims to make your site much more accessible to others, which naturally includes search engines. This in turn allows more users to get to your site and find your content (even if originally it was written in a language they can’t understand). This site serves as a perfect example, originally written in German, when its great content became translated (and therefor much more available) its reach skyrocketed
In my opinion, WPML is the most powerful WordPress multilingual plugin. WPML has a complete startup guide for new users and its side-wide navigation adds top navigation with drop down menus, breadcrumbs trail navigation and also sidebar navigation. WPML is rather too powerful for a simple multilingual website. You can have a lot of options and configurations through the backend admin menu. Adding a non-support language is not that easy. For example, when I tried to add a language which is not supported by default, I need to go to my MySQL backend and manually add in the SQL queries. Hopefully future version will make this easier.
qTranslate is yet another powerful multi languages WordPress plugin. It has advantages over WPML because it allows users to add new languages to the system through the Simplistic Configuration Page. In terms of URL structure, qTranslate provides three modes to make your URLs pretty and SEO friendly:- everywhere compatible ?lang=en, simple and beautiful /en/foo or nice and neat subdomain en.domain.com.
You can define multiple languages and translate posts/tags/categories using the interface that will be added to your blog’s administration panel. Adding a new user-defined language is very simple through the admin panel, but there are a couple of important things that you should check before adding a new language. For example, the language code and the language permalink. You can read more about this is the plugin website.
5. Language Switcher WordPress Plugin
Setting up the language switcher plugin to work with your WordPress site does take some work. The official website provides a very comprehensive startup guide which covers installing, theme and plugin modifications, translating and Q & A.
xLanguage is a full featured plugin which allows you to blog in different language. It works for blog post, page, tags and categories. xLanguage uses tags to differentiate different languages and serve the content to the user based on their selected language.