Changing the values of a question

Question 2: 
I didn't understand "single choice", thinking it was a one answer question (Using the term "multiple choice question- one answer permitted" would be much clearer.)

Further, you don't make it clear that single-choice means that one cannot answer AND leave a comment. Again, this is a very poor pre-set. Why isn't there an option for single choice answer with comment? 

Do I have to go back and redo all those questions, changing them to what you call multiple choice? 

Your question elements could honestly be much, much better. Have a look at Survey Monkey if you need to steal ideas. 

To clarify, single choice is using radio button while multiple choice is using checkbox. Radio buttons allows you single selection only while checkbox allows multiple selection.

If you want users to comment on the selection, just enable the "Other" option. That option is available in both single choice and multiple choice field.

Let us know if you have any questions or if you need further assistance. 

No, that's not how it behaves. Let me ask this another way:

How do I oblige the user to select ONE answer out of multiple choices, AND allow a comment, in the *same* question? 

"Other" is a choice, and if I enable only one choice, someone cannot select "yes" or "no" or "maybe" and leave a comment. Is this possible or not? 

How do I oblige the user to select ONE answer out of multiple choices? — Enable the Entry limit to a minimum and maximum value of "1" and set the field as required. User will be obliged to fill the multiple selection field.

Allow a comment, in the *same* question? — Maybe you can add a field that will only be visible when the multiple choice is filled. 

Check my sample here https://form.jotform.com/90858341109964