In case you already created a question with given question type, it is not possible to change the type.
Example:
If you create a single choice question (where respondent select only one answer) it is not possible to change the setup to, for example, multiple choice question type (where respondent can select more than 1 answer).
In case you want to change the question type, you need to create a new question again with the correct question type and create the question again. Then delete the original one with incorrect question type setup.
