This feature is included in the Enterprise and ReportR plan.
Want to give a helping hand to your respondent? You can add a question hint to help out those who are struggling. When you've activated this feature, a small question mark will appear above the question. If the respondent clicks the icon, they'll get a popup with additional information or a hint.
To turn on question hints, head to the Extra options tab and scroll down to Private Options. Toggle to turn on Question hints.
Now when you go back to the questionnaire editor, you'll see a text box underneath the question text box and question options where you can enter your hint.
Here is how the question hint icon will be shown:
By clicking on the question mark icon, the hint will be displayed above the question: