LEX: Greetings and Polite Expressions

The first LEX thread was in the Language Factory, but that seems to be where more theoretical work is going on, and this seems to be where words are getting made and put together with other words, so I am proposing this second vocabulary module here.
This might be a good place for people to bring out some cultural thoughts. The following are just represent the English equivalent of some things we might want to cover with set expressions. Please add more as you think of them.
Hello/Goodbye (Some considerations, for example: Are there different expressions if you're the one arriving/leaving or the one staying? Or is the greeting a word with a recognized meaning, like "Peace"? Are Hello and Goodbye the same word?)
Please/Thank You
Yes/No
How are you?
I am fine.
This might be a good place for people to bring out some cultural thoughts. The following are just represent the English equivalent of some things we might want to cover with set expressions. Please add more as you think of them.
Hello/Goodbye (Some considerations, for example: Are there different expressions if you're the one arriving/leaving or the one staying? Or is the greeting a word with a recognized meaning, like "Peace"? Are Hello and Goodbye the same word?)
Please/Thank You
Yes/No
How are you?
I am fine.