Complex sentence: Each house is run by a housemaster, who is also an active member of the teaching staff, and each year group within a house is run by a tutor who monitors the pupils' academic progress, general welfare and extra-curricular involvement.
Split into simpler sentences: Each house is run by a housemaster, who is also an active member of the teaching staff. Each year group within a house is run by a tutor who monitors the pupils' academic progress, general welfare and extra-curricular involvement.