When the lecture did not land.
THE INSTRUCTION THAT MATTERS
Specify your level.
"Explain [concept] to someone who has never studied this." "Explain it to someone who understands [related thing I do know]." "Explain as though to a twelve-year-old."
That last one produces genuinely clearer explanations at any level.
THE PART PEOPLE SKIP
Follow-up questions.
"I did not follow the part about X. Explain that differently." "Give me an analogy." "Give me a concrete example."
You can ask as many times as you need. Nobody is impatient.
ASKING SEVERAL WAYS
"Explain this three different ways."
One usually clicks.
WHAT TO VERIFY
Against your actual course material.
A fluent explanation of something the model has wrong is convincing, and your exam follows your syllabus.
WHEN IT CONFLICTS WITH YOUR LECTURER
Your lecturer sets the exam.