How can I insert a two part question

I am not quite sure what you mean by two part question.  If you need to show an additional question based on the selection made in a previous question, you can do so using conditional logic:

https://www.jotform.com/help/316-How-to-Show-or-Hide-Fields-Base-on-User-s-Answer

If there is something else you are looking for, let us know and we will be happy to help.