In order to create a Multilingual Site, you have to use a translation plugin. Multilingual plugins offer WordPress users the ability to run a multilingual site with a single WP install.
The multilingual WP plugins are free and premium (paid). The most popular premium plugin is WPML.
WPML (Tested with all VamTam themes)
We recommend you using this plugin. It is well worth the price.
WPML is a premium multilingual plugin, designed to make it easy to build and run multilingual sites and blogs, and translate pages, posts, and other content. The default install offers more than 40 languages, and users can arrange different language content in the same domain via language directories, in sub-domains, or in completely different domains.
One of the other cool features of WPML is the ability to translate comments, so when international visitors comment in languages you don’t speak, you can read them and reply. As a premium plugin, the cost runs between $29 for blogs, and $79 for websites.
See our tutorial How to set up WPML?
See also the official WPML page
FREE Alternative to WPML
See our tutorial How to set up the Polylang plugin?
Polylang is another free plugin via the WordPress Plugin Directory, adding multilingual content management support to standalone WordPress sites. WordPress language files are automatically downloaded and updated, so you can translate posts, pages, media, categories, post tags, menus widgets and more.
Polylang has been downloaded more than 117,000 times, and has an average user rating of 4.9/5 stars.
Polylang is a bit younger than qTranslate, but is coming along quite nicely. It creates entirely different posts for each defined language, which makes everything a bit cleaner. However, it has a bit of a steep learning curve, as it doesn't come with an installation wizard that lets you set up everything right from the start.
See also the official Polylang page
Mind that if you’re the least bit serious about having a multilingual WordPress site, we don’t recommend you to use Google Translate to do it. Not only are automatic translations very inaccurate, they may also cause Google to penalize you for having essentially duplicate content. Always consider having an expert translator do the job instead.