Greetings In Spanish
Hola means 'hello' and is the most common initial greeting.
Adios is an informal way of saying goodbye, but can also be used when you see someone you know and you do not stop to have a conversation.
Buenos días is 'good morning'.
In the afternoon and evening Buenas tardes is used.
Buenas noches is 'good night' and saying 'goodbye' at the end of the day, e.g. when leaving a restaurant. It is also used later in the evening as an opening greeting, e.g. on arrival at a restaurant.
When you say goodbye, phrases like Hasta luego, Hasta pronto, Hasta ahora are used when you expect to see the other person soon.
Hasta mañana is used for 'See you tomorrow' and Hasta el lunes, (etc) for 'See you on Monday', (etc).
In Latin America Chau is commonly used informally for goodbye (like Italian Ciao). In Mexico, Ahorita is very common for goodbye.
When you answer the phone,¡Dígame! or ¡Díga! is used in Spain, ¡Aló! in South America, and ¡Bueno!in Mexico.