can't make a pdf

Are you referring to create a PDF form? 

This guide will help you: http://www.jotform.com/help/212-How-to-Create-a-PDF-Form. 

Are you referring to download your submissions as PDF?

This guide will help you: http://www.jotform.com/help/73-How-to-Partially-Download-Form-Submissions-as-Excel-CSV-PDF.

If it does not help, please provide us more details, we will be glad to help you.