Hello Kansas girl
Your situation sounds totally like ours - our school is just coasting and doesn't push the children. Lots of verbage about developing at their own speed and bringing out the creativity in them - but I've yet to be really impressed by a field trip or a class activity after 5 years + at this school. Same field trips year after year - very little effort to link history/ geography/ science units with field trips - no attempt at showing real world application of maths.
The main advice I had from folks here on Mumsnet was quite simple and very liberating - if they're not going to help at school (and it sounds like your school has all sorts of issues) then you need to help at home.
Now I'm not sure what your situation is but these were our solutions:
We joined an on-line maths tutorial - We use mathsfactor, but others have written to discuss mathswhizz and mathletics with equal praise. Basically search them on google and have a look. They all offer free trials and because it's structured, you just have to keep a notional eye that they're putting in the time (about an hour a week for 5 mathsfactor homeworks).
We started borrowing/ buying lots of books that were age appropriate (for DD2 who is a strong reader) or reading age appropriate (for DD1 who is a weak reader). We insist on reading every night. Sometimes with us, sometimes us to them (so we're currently working through the Lemony Snicket series - but also discussing words and meanings, we've also read some of our own chidlhood favourites like Charlottes Web and last Christmas we read A Christmas Carol together) and most nights tuck them up in bed with a book with lights out 20 - 30 minutes later.
As lljkk suggested get him writing. But be sneaky about it. Thank you cards (great source of joy to relatives) and gets that practice in. Postcards on holidays/ days out. Writing in to competitions (don't just send that e-mail) from magazines/ books. Writing to Father Christmas. And we found we had great success 'cheating' on spelling words. Instead of writing 10 sentences for each word - we started a game of trying to use all the words in as few sentences as possible and a prize for a single sentence. If there's writing related work - just check to see that they're not writing the bare minimum. The result was better understanding of word meaning and use and some good fun with double meanings - we also got more writing in the end by accident.
With hands hurting - we also have a left hander - we actually twigged that the problem was our DD1 rarely writes in school. So we took her to a fancy office supply shop and let her chose and purchase a really nice little notebook. We also bought the stablo left-handed pens - which she finds very comfortable to use.
You have to accept this is going to take time - maybe years. But my advice is don't wait on the school to do something. You start with what you can (and it sounds like you can help a lot with English) and just try and add about an hour a day (which actually is less than most children spend on watching tv or playing video games). Gradually you'll make up that lost ground and your son will learn a truly crucial lesson - you get as much out of something as you put in.
finally use the power of a search engine. Literally type in preposition worksheets KS2 - and see what you get. There are tons of great, free resources out there. I even joined Times Education Supplement so I could access support materials - just sign up as a volunteer (if that option is still available).
quick list of great websites:
Woodland Junior school: www.woodlands-junior.kent.sch.uk/
Great links for all sorts of areas of curriculum
Crickweb: www.crickweb.co.uk/Key-Stage-2.html
Just select KS2 on the blue horizontal menu bar and then scroll down to appropriate area of curriculum
BBC Learning [BETA]: www.bbc.co.uk/schools/teachers/
Select KS2 on tab in orange box (middle left) and then just select appropriate area of curriculum and follow through to area you're after.
Ambleside primary: www.amblesideprimary.com/ambleweb/numeracy.htm
literacy or numeracy hour have great links to excellent resources
HTH