Complex sentence: A pupil applies to become a prefect in Year 10, writing their qualities & why they're suitable to be a prefect, in Year 11, there is one head boy & head girl with a deputy head boy & head girl.
Split into simpler sentences: A pupil applies to become a prefect in year 10, writing their qualities and why they are suitable to be a prefect. In year 11, there is one head boy and head girl with a deputy head boy and head girl.