Could you please check these last two sentences, again? Thank you.

1) On one hand, I think it would be best to organize a student exchange program for next autumn and, on the other hand see the number of students who would be interested in spending an academic year at your school.
2) By the way, how do you plan to organize the email partnership?
What do you think of my proposal? I would like to start next week with it.

1) First, we should determine the number of students who would be interested in spending an academic year at your school. Once we know the numbers, we can organize a student exchange program for next autumn.

2) OK

I didn't pick up on this before, but you should use "on one hand ... on the other hand" when you are setting up a contrast (opposing ideas). Your first sentence here, however, is setting up a two-step process: 1) find out how many; 2) organize the program once you know if there are enough people interested.

1) I would be happy to help you with the sentences. Let's take a closer look at them:

The first sentence: "On one hand, I think it would be best to organize a student exchange program for next autumn and, on the other hand, see the number of students who would be interested in spending an academic year at your school."

In this sentence, you are expressing two contrasting ideas. To improve the clarity and structure, you can make a small adjustment. The phrase "see the number of students" could be replaced with "determine the level of interest from students." Here's the revised version:

"On one hand, I think it would be best to organize a student exchange program for next autumn. On the other hand, we should determine the level of interest from students who would be interested in spending an academic year at your school."

2) The second sentence: "By the way, how do you plan to organize the email partnership?"

This sentence seems grammatically correct and clear. However, it might be helpful to add more context and provide some specifics about the email partnership you are referring to. For example, if you mention the purpose of the email partnership or any specific details, it will help the person you're communicating with better understand your question.

Regarding your proposal to start next week, that depends on the response you receive from the other party. It's always a good idea to confirm their availability and agreement before proceeding with any plans.