Important Classroom Phrases

I don’t understand.

I don’t know.

Pardon? / Excuse me? / I’m sorry, I didn’t hear what you said.

Can / Could you repeat that, please?   
Would you mind repeating that, please?

Could you say that again, please?  / I'm sorry, I didn't catch what you said.

Do you mind if I open the window? 

                            Yes, certainly.       /   Please don’t. It’s very cold.

May I please go to the restroom/toilet?

How do you spell “maintenance”?

                            m-a-i-n-t-e-n-a-n-c-e

How do you say “manutenzione dello scafo” in English?

                            We say “hull maintenance.”

What does “hull maintenance” mean?              

         It’s the care or upkeep of the hollow, lowermost part of a boat or ship.”

Could you please explain what "hull maintenance means"? 

It's not easy to explain what I mean. 

What am I supposed to do? 

What would you like me to do?
Could you repeat the instructions, please?