I have a problem since I'm in England for my studies, I never know what to say when I meet someone. To my friends, I always say "Hi". But I would like to know if "Good morning" would sound too formal? Once, I said to a girl: "have a good evening", and she told me it sounded a bit posh. The same problem with people I don't know. I was shocked to hear the cashiers at Tesco telling me "Hi ya" or something like that. Should I say "Hi" to a cashier? In French, I would never say "Salut" to a supermarket's cashier, but "Bonjour"! Another thing is the word "cheers". Is it much less formal than "Thank you"? Can I say "thanks" to my teacher? Can I say "cheers"? Once, my teacher (who is quite young and even put his feet on the desk!) send us an e-mail with "cheers guys" at the end. Is it common between teachers and students? Last thing: is "How are you" quite formal? Because I don't hear young English people saying that. They would say something like: "You're alright?". What about "How are you doing?" As you can see, after 3 months in England I'm still a bit confused! Thanks for your help!