What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
You need to have a translation to your form, you can check this guide on how to make your form multilingual: http://www.jotform.com/help/298-How-to-make-your-forms-multilingual.
After you have setup the languages that you want, make sure that the language in your website is also included in the language translation of your form.
Click the "Options" in your Form Language settings.
Make sure that you tick or enable the "Detect user browser language".
I hope this helps.