Here's why:
* Closed-ended questions require a simple "yes" or "no" answer. "Certainly" implies a strong affirmation, which is not appropriate for a question that requires a binary response.
* "Certainly" is typically used in responses to indicate agreement or confirmation. For example, "Are you coming?" "Certainly."
Here's an example of how using "certainly" in a closed-ended question can be confusing:
* Incorrect: "Certainly, are you coming to the party?"
* Correct: "Are you coming to the party?"
Instead of using "certainly," you could use:
* "Definitely" for a strong affirmation
* "Are you sure?" for clarification
In summary, stick to simple and direct language when asking closed-ended questions. "Certainly" is better suited for affirmative responses.