Here's how to add a language in OpenCart step-by-step:
- Download the language pack you need. You can search the OpenCart marketplace. Don't close this browser tab.
- Unzip it an upload the files to your main shop directory. Note: If there is an
uploadfolder inside the archive, upload the contents of that folder, not the folder itself.
- Go to OpenCart admin>System>Localisation>Languages
- Click "Insert". The details that you have to fill in the form are usually supplied in the "Documentation" tab on the OpenCart extension page of the language pack. You might also find them in a text file inside the installation archive.
If you have trouble installing a language in OpenCart, let me know in the comments.