French phrase
Je n'ai pas compris, pouvez-vous ~ ?
Meaning
I didn't understand, could you ___?
When to use it
A courteous request for someone to repeat what was said. It is used after something has not been understood.
Example dialogue
Je n'ai pas compris, pouvez-vous répéter ?
I didn't understand, could you repeat that?
Bien sûr, je répète.
Certainly, I'll repeat it.