How can I help my four and a half year old to switch off at night

[Peanuts33]

DS started school in September. He usually goes to bed between 7 and half past and used to go to sleep straight away. Since he has been at school he lies awake until 10pm some nights and I can hear him talking to himself about phonics and numbers and what has happened during the day at school. He is so tired at the moment and is really grumpy during the day but when it comes to bed time he just cant seem to switch off. I feel so sorry for him that all he is thinking about at the moment is school school school.

What does he do after school? Does he play outside enough?

I have old-fashioned views and think DCs need to spend a lot of time playing in a playground/park/garden burning off physical energy and airing their heads after school!

I would agree-lots of physical exercise. Put old clothes around, get dirty and run!
Bath and story before he goes to sleep-the story read when he is in bed. Try a chapter book and leave it at an interesting place so that he is thinking about the story and not school.