Good morning. One part good, one part morning. A few people say this to me at work: Pete, Cyril, Nicky, Taylor. Because I am Mr Literal, I choose to take it at face value — good morning. My response varies from “I’m with you on the ‘morning’ part” or “not really” to, if I’m feeling nice, “hello.” I almost never say “good morning” because if I had to get up at 7:22 to go somewhere I don’t want to be, then it’s decidedly not a good morning. I feel I have a right to be cranky under the circumstances. I certainly don’t expect anyone else to be chipper at the prospect of being on their feet for the next 7 hours.
Other people, the more “homey” types, say “what’s up?” instead of “good morning.” I don’t think it’s actually a question, but I answer it anyway. Usually with “books.”