Language in Ohio and Illinois

Dear reader,
concerning the usage of English I have already learned alot during the last week. If I remember how unsure I was in the beginning, ont knowing if I should say "Hello" or "Hi" (I didn't know if "Hi" is informal and all these things). To be honest it took like 5 minutes in the US until Chuck came and said something similiar to "Hey, what's up". At this point I knew a "Hi" would do it :)
All in all I would say that the way of speaking is very different to what we have learned in school, what is quite sad to me, since I learned english for 9 years in school but still I feel like I got some problems. Still I would say that I am quite lucky since my uncle is from the US and by talking to him I got used to some more informal style of speaking what definately helps me!
A difference between English and German is for example the way of greeting someone. In Germany it is simply "Hello" when you enter a store, but here they say things like "How are you" or "How is it going" which is unusual in Germany since it would show some interest in the answer. In the US it is more a set phrase and the answer is quite unimportant, cause you say good or fine, no matter how you actually feel.
What I have learned about language since I am here is that you just have to say what comes to your mind. People will correct you if something is completely wrong and they will understand most of the things you say. But the more you speak, the more you get used to it and it gets more and more easy. The most important point to me is for example at Chuck's house we had a barbecue and by speaking English the whole night you start thinking in English, what makes a conversation much easier, since you don't need to transfer your thoughts into a different language.
After being here for more than one week, I would not say that my English has changed that much, since I don't think that I speak different. The thing that changed is on the one side that I feel much more comfortable by speaking, since I know that people will understand me and on the other side the listening part. It is obvious that our teacher in school spoke different than people here and sometimes it is really hard to understand, especially when you are talking to mexicans', since they have this very "bad" slang and they tend to swallow the endings of words and sentences. Still a conversation works, since they realize that you don't get a word of what they are saying after the third time of saying "sorry".
All in all my attitude towards the language itself didn't change but my attitude towards speaking it did. By feeling more comfortable while speaking you start talking more and that is the best way to improve your english.