Could you please repeat that?
When someone is learning English, he/she may sometimes not understand what the teacher said. How would they ask their teacher?
1. If you did not hear what the teacher said, you can ask “Could you please repeat that?” or “Could you say that again?”
These are very common phrases.
2. What if you didn`t understand what the teacher said? You can say “I`m sorry, I don`t understand.” or “I`m sorry. I didn`t understand that.”
Other questions you can ask are “Could you explain that?”
3. What if you want the teacher to speak more slowly? You can ask “Could you please speak more slowly?” or “Could you say that more slowly, please?”