Where are the greetings?
The first subject we teach students are the greetings in English.  We create situations in which students will have to use "Good morning", "Good afternoon",  "Good evening" etc.  When I arrived in US and say any of these greetings, people just say "Hello, how are you?" all the time, in every situation.  Instead of saying goodbye, they prefer saying "Have a nice day" or "Have a nice night".
Despite of the fact that  they sometimes say "Good morning" or "Good night", it's not their preference.
Where are the greetings???
I think I'm gonna have to change this subject when I return to Brazil.