If you are creating another questionnaire draft, in which you want to use previously added questions from another survey, go to the CREATE -> Add a question or text tab.
Then, at the bottom you will find the option "Paste question from another survey".
After clicking on a given field, a list with the titles of your surveys will expand. Select the study you are interested in and select the question that you want to add to the new project.
After selecting the question, confirm it by clicking on ADD QUESTION: