Complex sentence: The school does not to set homework for its pupils, but instead has an extended school day finishing at 4:30 on Monday and Friday on Tuesday, Wednesday and Thursday they stay till 5:30 to do electives an activity of the students choice such as Choir or Football.
Split into simpler sentences: The school does not to set homework for its pupils, but instead has an extended school day finishing at 4:30 on Monday and Friday. On Tuesday, Wednesday and Thursday they stay till 5:30 to do electives an activity of the students choice such as Choir or Football.