Which field is best to use for open-ended questions?

Hi.  I created a client intake form for my nutrition practice.  I have asked many open ended questions in the form I have created, using text boxes.  

Does the client have any max character limits?  I am thinking I should have used text areas instead of boxes for open ended questions that will take several sentences to answer. Is that correct? If so, what would be the easiest way to change all of these on my document?

Thank you.

I have checked your form, https://form.jotform.com/60787060836159, and I can see that you might have changed most of it already as I'm not seeing any question that would require several sentences to answered and still has a textbox field only. With regards to the limit of character, there is none unless you set a maximum character through the fields properties. Actually, you are correct, it would still be best to use text areas for open-ended questions.

Also, there is no other best way for you to replace those textbox fields with text area fields other than doing it manually. 

By the way, these guides might be of help and you may use them also as references.

How-to-Create-Your-First-Web-Form

10-Best-Practices-for-Web-Forms