The person who asks how to check the result is trying to learn responsibly.

Asking how you will know it worked is a different question from asking how to do it. It shows someone is thinking past the moment of the task to the moment of consequence. That question can sound like a lack of confidence. It is closer to the opposite: an unwillingness to hand back work they cannot vouch for.

Teach the check as part of the method rather than as an afterthought. Say what right looks like and what the common wrong looks like. And when someone asks you how to verify something, treat it as a good sign and answer it properly.