It quite simple ... Go to the survey editor and press "add new question" in the upper right hand corner.
1. Add your question and the possible answers that you want for the question.
2. Click "use a template" if you want to use one of the predefined answer categories.
3. Choose whether your question is "personal" or "opinion".
4. If you feel that it's important that everyone is asked this particular question (normally questions are asked randomly) you should check the box "ask everyone".
5. Chain the question to another question if relevant - learn more.
6. Press save
Please note: You need to activate the question from the main survey editor menu before it becomes active in your online survey.