1. Sitefinity enables to localize a website in as many languages as required. When the website is created the default language is English (default language cannot be deleted). You can create different languages for the frontend of your website as well as for the backend. Frontend and backend languages can be created independently. This document is about frontend configuration.

2. Navigate to Basic Settings. Go to Administration -> Settings -> Languages.

3. To add a new language, click on “Add languages”. The Select languages window appears, displaying a list of all languages available. Select the language. If you want to add different language cultures, click “Show cultures”. When you finish click on “Done”

4. The selected languages are added under the Enabled languages for public content section. Each must have one default language. For each additional language, the system displays the  “Delete” icon.

5. When you added more that one language, the Multilingual URL section will appear. This will set up how the URLs of the pages will appear in each added language. This will work for both single site and multiple sites.

You have to choose between the following:

a. Directories: You use one domain and the every language versions are represented by different, automatically created directories.

b. Different domains: You use different domain names for each language that you have added.  In each field, enter the respective domain name. For each language, add language-specific domains for all your sites in a comma-separated list. 

Let's take for example, for English you can have a list that contains site1.domain.com, site2.domain.com etc. And for German you can have a list that contains site1.domain.de, site2.domain.de, etc. The same rule applies to culture specific domains, for example: site1.us.domain.com, site2.us.domain.com.

6. When working with multisite mode, you need to add the language for each site. For each language, add language-specific domains for any of your sites in a comma-separated list.

a. Navigate to Manage Sites

b. Select the site, in “Actions” link select “Properties” option and then in Languages section add the languages.

7. Click on save Changes.

8. Note: By default pages in the default language do not have language prefixes in their URLs.  Sitefinity allows to change this behavior. If you have created all the languages in directories, by default, pages will not have prefixed in ther URLs. So, if you have English as your default language and Spanish as the secondary one, the URLs will look link this:
-In English: www.mysite.com/contacts
-In French: www.mysite.com/fr/contacts
If you want the English page to have the name of its directory in the URL, do the following:

a. Click Administration -> Settings -> Advanced.

b. In the tree view on the left, expand Resources -> UrlLocationsStrategies ->SubFolderUrlLocalizationStrategy -> Parameters and click create new.

c. In Key enter includeSubfoderPrefixForDetailLanguage.

d. In Value, enter True.

e. Save your changes and restart the application.