Which class are you in?

I'm in class 2.

What class are you in?
I'm in class 2.

Which year and which class are you in?
I'm in the second year and the second class.

What year and what class are you in?
I'm in the second year and second class.
I'm in the second year, second class.

(Would you check the questions and answers? Do I have to use 'Class 2'? Do I have to capitalize 'c'?)

Everything looks OK. No, you don't need the word "class." = I'm in 2 could answer "Which class are y ou in?"

Only capitalize Class if you are using it as a proper name.

Sra

Write a letter to my friend in another school telling him/her three things you like most in your school, and why you like those things.

In formal English, when referring to a specific class or year in an educational context, it is common to use capitalized Roman numerals or numbers. Therefore, you can write "Class 2" or "Class II." The same applies to the year, which can be written as "Year 2" or "Year II." However, in informal speech or writing, lowercase letters and Arabic numerals can be used, such as "class 2" or "year 2." Both forms are generally acceptable.

To clarify, here are the revised versions of your questions and answers:

Question: Which class are you in?
Answer: I'm in Class 2.

Question: What class are you in?
Answer: I'm in Class 2.

Question: Which year and which class are you in?
Answer: I'm in the second year and Class 2.

Question: What year and what class are you in?
Answer: I'm in the second year and Class 2.
Answer: I'm in Year 2 and Class II.

Please note that these are general guidelines, and the specific conventions may vary depending on the educational system or institution you are referring to.