I urgently need your help to find the proper words. Thank you.

1) Thank you very much for answering my email. I hope you don't mind me writing in English (to you) instead of German. Feel free to answer in German.
2)I'm very pleased to start working with you on a common project in which our lingua franca will be English.
3) I believe we can start with the email partnership straigh away.
4) I was thinking of including students from classes 10 and 11, who are preparing for their PET certification. They are actually learning colloquial English used in everday conversations.
5) As I will have to follow them with their English translations, I was wondering if we could choose subjects like art and history for our future project.
6) It would be much easier for them to express themselves in such subjects.
7) Furthermore, I know your school has got a bilingual branch in which such subjects are already taught in English.
8) Since our students will have to learn a subject in English in their last year of school, I think they will profit a lot from this project.

1) Thank you very much for answering my email. I hope you don't mind if I write to you in English instead of German. Feel free to answer in German.

2) OK

3) I believe we can start with the email partnership right away.

4) OK

5) Because I will have to follow them<~~I don't understand what you mean here. with their English translations, I was wondering if we could choose subjects like art and history for our future projects.

6) OK

7) Furthermore, I know your school has a bilingual branch in which such subjects are already taught in English.

8) OK

1) The first sentence seems perfect as it is, conveying gratitude and a question about language preference. Well done!

2) The second sentence is also well-written, expressing enthusiasm about working together and stating that English will be the common language. Great choice of words!

3) The third sentence is clear and straightforward. However, you can improve it by using "straight" instead of "straigh." So it should be "straight away" instead of "straigh away".

4) The fourth sentence is clear in terms of who you want to include in the project, but there are a couple of issues with the wording. You can rephrase it as follows: "I was thinking of including students from classes 10 and 11 who are preparing for their PET certification. These students are currently learning colloquial English for everyday conversations." This way, it provides more clarity about the students' current language focus.

5) The fifth sentence is good, but you could make a few improvements. It should be "As I will have to assist them with their English translations" instead of "As I will have to follow them with their English translations." Additionally, you can replace "subjects" with "topics" for clarity. So, it would become "I was wondering if we could choose topics like art and history for our future project."

6) The sixth sentence is clear, but you can enhance it by using the word "easier" instead of "much easier." So it should be "It would be easier for them to express themselves in such topics."

7) The seventh sentence is concise and has good information. However, you can rephrase it to sound more natural: "Furthermore, I am aware that your school has a bilingual branch where such topics are already taught in English."

8) The eighth sentence is well-written and effectively conveys your point. No changes needed here.

Overall, the writing is clear, but there are a few minor improvements you can make for better clarity and fluency.