Poedit is a software which you can use to translate language of your plugin content or theme. ‘English(United States)’ is default language for wordpress but you can change its language easily in following steps. Here is complete list of Languages Codes and Country Codes.
Change language of your plugin content
Step 1 To change languages of your plugin contents , we use poedit software.
Step 2 Open Poedit and click on “File/Open…” and Select the .POT file or the .PO file from the plugin you wish to translate which (you can find the files in the wp-content/your-plugin-path/language/ folder).
Step 3 Now you have to change the language file for your language.Then go to catalog menu-> Properties file.
Step 4 A box will pop up asking for language of the translation. Select your language and click ok.
Step 5 Now you can start translating your plugin content- just go through every line of text and translate it to your native language.
Step 6 When you’ve finised save your file with your language code (for example de_DE.po). Poedit will automatically create both .po and .mo files.
Step 7 Upload the file to your /languages folder : Below is screenshot of .po and .mo files for German languages. Upload your files to the languages folder you just created. For e.g ‘wp-content/your-plugin-path/languages or lang’ folder.
Step 8 Change the language in the admin settings : Then switch your wordpress dashboard and go to Settings -> General -> “Site Language” setting.
Step 9 Select the language option corresponding to the .mo file you just uploaded and click on Save Changes.
Step 10 Refresh your page and you should see your plugin contents in German language.