When you click on Add Language, you are asked to select the new language that you’ll be adding. Then, you will need to press the Customize button that appears on mouse hover.
Note: Messages and fields can be translated from the Basic plan, but if you want to add multiple languages to the form, you’ll need to upgrade to a paid plan.
From there, you’ll be taken to the customization lightbox pictured below, where translations are created. On the left side, there are listed all the form fields that you’ve created and all the messages that form users may see while filling out and sending the form. Add the translations in the text boxes on the right side. Press Save when you’re done.