1) Hello, I wonder if you can help me. I have an X3000 digital camera that I bought from a shop in Chicago that has since gone out of business. The camera is great, but I have lost the user manual. Could you please tell me where I can find one? I’ve looked on the internet, but without success. Thank you. Kate Winslow
2)Dear Sir/Madam, I bought a KJ450 printer from your online store three months ago, but it is very slow. I would like to return it and get a refund. Please can you advise me how to go about this? Yours sincerely, Kevin Lyons
3)Hi Jim, Thanks a lot for the advice about the car. I changed the air filter, and it’s running much better now. Just out of interest, do you know what kind of oil is best to use with an old car? If so, can you drop me a line and let me know? Cheers, Nathan 4)Chris, Would you mind stopping over to take a look at the air conditioning in my apartment? It’s making a strange noise. I’d be really grateful. Please don’t go out of your way , though. Anytime in the next week or so is fine. All the best, Sophie

1) What is the relationship between each pair of correspondents?
2 Which are big requests, and which are small requests?
3 Which phrases for requests and apologies are only used formally? And informally?