Can I translate any form into Spanish?

Yes, you can. There are no limits in translations.

To do that I would suggest the following guides:

How to make your forms multilingual?

 - For general translations

How to Change Form Warnings

 - If you wish to first adjust some warnings

How to change thank you message depending on the language used?

 - If you wish to go a bit further and change not only the text of your form, but of the thank you page, this is the guide to check.

How to change thank you message depending on the language used?

 - How to change the email templates sent based on the language set on your form.

These 4 guides cover all aspects of translation possible on your jotform, but if you have any questions along the way do let us know and we would be happy to assist with the same.