To add new language for your site please follow the following steps-
1.Firstly, You need to add a language from admin panel.
2.Click on Add Language Button then the next form will come for adding language.
3. Remember the Short name of the language.
4. Then go to this file location resources\lang and then copy a folder from existing one.
5. Then rename the copied folder with your language short name.
6. Convert your desired language in messages.php file .
7. Here, left side contains English language and right side will be filled up by your converted language.
8. Save your messages.php file for all.