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.
I presume that this is about "How to change the language on my jotform?" rather than "How to change the language of my interface?". If not, do let us know.
Now to change the language of your jotform you should follow the steps shown here: How to make your forms multilingual?
Of course if you have any questions along the way feel free to let us know and we would be happy to answer them.