Etsy allows users to operate their shops in multiple languages. You are able to select any number of these languages or just stick with your default. To update your languages you need to go to Etsy's Languages and Translations page.
If the link does not work follow this path:
Log in to Etsy
Navigate to Shop Manager
Settings
Language and Translations
Once there click "Manage languages".
Clicking that will open the following popup. Slide the slider to the right to select which language(s) you want in your shop. Once selected click "Save changes".
Now that you have enabled translations on your Etsy shop, visit How do I add translations to my templates? to add them to your templates!