In order to create a Multilingual Site, you have to use a translation plugin. Multilingual plugins allow WordPress users 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)
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 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
Polylang
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 that 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 different posts for each defined language, making 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
Translate Wordpress with GTranslate
Features:
Free Google automatic machine translation
Hides “Suggest better translation” pop-up
Hides Google top frame after translation
Mouseover effect
Google Analytics integration
Translates the site on the fly
Posts and pages translation
Categories and tags translation
Menus and widgets translation
Themes and plugins translation
Right to left language support
Google language translator widget
Auto-switch language based on browser defined language
Available styles Dropdown, Flags, Flags with dropdown, Nice dropdown with flags, Flags with language names, Flags with language codes, Language names, Language codes, Globe, Popup
Floating language selector
Language bar with flags in menu
WooCommerce shop translation
Multilanguage
Multilingual language names in native alphabet
Multilingual interface
Alternative flags for Quebec, Canada, USA, Brazil, Mexico, Argentina, Colombia
Lazy loading for language flags to boost performance
See also the official Translate Wordpress with GTranslate page