Useful English for the Classroom

The instructor might say:

Do you have any questions?
Do you understand the question?
Was the passage/chapter/exercise difficult to understand?
Is there anything that you did not understand?
Do you understand the question/my English/what I am saying/this word?
Taro, please answer the question.
Please open your books at page two.
Please look at the checklist on page six.
Please read chapter one.
Please do exercise three for homework.
Please be quiet/stop talking.
Please form groups.
Would you like to be in the same groups as last time?
Please pass your homework up to the front.
Please exchange your homework with a friend, and check your friend's homework while your friend checks yours.

The students might say:

Dr Ballhatchet, I have a question.
I do not understand the word 'salmon' in the second paragraph on page four.
I do not understand the second sentence in the third paragraph.
I do not understand your question.
Could you say that again please?
(You are speaking a little fast.) Could you speak more slowly please?
I cannot read your writing. What does this word/this part say?
Why is this wrong?
I do not understand your correction.

Note: In English, you should address instructors by title (Miss/Dr/Professor etc.) + last name (or if the class has an informal atmosphere by their first name, without any title), NOT as 'Teacher'.