You may be able to do something within the browser as a translate, but currently Nintex Workflow Cloud only supports English. We are aware of the need and are planning to address this as we continue releasing updates overall. Thanks for using the product and if you have feedback, please post them here Customer Feedback for Nintex
Has this issue been addressed? I still have an issue with a german site where the nintex form and the dialog text (eg. for Upload a file - says "select files") is in english instead of German.