Greetings

Good morning - 
The answer to this greeting can be “Hi, Hello or Good morning.”

Hi - 
This is the most common way to greet somebody. You might want to use “Hi there” if you already know the person. The answer to this greeting can be “Hi, Hello or depending on the time of day, “Good morning or Good evening.”

Hello - 
This greeting is appropriate under any circumstances, even on the phone. The answer to this greeting can be “Hi, Hello or depending on the time of day, “Good morning or Good evening.”

Good evening - 
Use this after about six in the evening and only if you want to appear a bit more formal than usual. The answer to this greeting can be “Hi, Hello or Good evening.”