Yes, you may make changes while the survey is live.
However, keep in mind that if you make any structural changes (move questions, delete options, delete or move pages, chance question type, logic etc.) to you survey, it will impact the data layout.
While making changes to the survey, respondents will not see the new changes until you publish the survey.
Important Note: If you survey is restricted and you have “Save respondent position” checked off in deployment setup, then respondents that have started the survey but did not finish, when they re-accessed the link will not have access to the new changes.
We advise that you pause the survey and make sure that no respondents are connected before making any edits to your survey.