I tend to use Good Morning and Good Afternoon fairly often when at work, and used Good Morning when I go out for early morning walks to other fellow early bird walkers like me. The rest of the time it'll just be Hi or Hello.
Good morning in emails, texts and in person, always. Rarely good afternoon and good evening, rarely. Hi in person. Hi or hello in email and texts, depending on to whom. I've tried to teach the grandkids to use greetings. I think it is working as they get older.
When school is in session, I say "Good Morning" about 50 times every single morning. It doesn't matter if it's other teachers or students.... it's the normal greeting. And heaven help me if I walk through the cafeteria before school! I don't seem to have as many "Afternoon!" greetings... but they happen some. Now, during the summer, when I'm out on my walks, I usually greet other people I pass with either a morning! if they're not wearing earbuds. Unless they're the guys on the lawnmowers and then we just wave at each other.
I grew up in a different time. It’s a sign of respect that I still adhere to as well as a way of defining…roles in a society that’s changing its idea of etiquette.
DGD and I have conversations about her life in France and told me manners are still more formal than here. Same is true in the Caribbean too