Buenos días, buenas tardes, buenas noches
This is the first part of the formal and very common greetings in Spanish.
In Spanish we have different ways to greet in a formal way depending on the time of the day.
In the morning we would say “Buenos días”, the translation in English would be “god morning”
for example when you go out of your house in the morning you greet your neighbors by saying “Buenos días”, or when you meet your teacher at school you say “Buenos días”, in your work place you greet coworkers saying “Buenos días”, when you wake up in the morning you greet your family saying “Buenos días”.
This is the first part of the formal greetings the second part will be buenas tardes & buenas noches. See you soon