Formal:
* Buenos días: (Good morning) - Used until noon.
* Buenas tardes: (Good afternoon) - Used from noon to sunset.
* Buenas noches: (Good evening) - Used after sunset.
Informal:
* Hola: (Hello) - The most common greeting, used in all situations.
* Qué bolá? (What's up?) - A more casual greeting, often used between friends.
* ¿Qué hay? (What's new?) - Similar to "qué bolá?", but slightly more formal.
* ¿Cómo estás? (How are you?) - A polite greeting that implies you are interested in the person's well-being.
Even More Informal:
* Hey: (Hey) - A very informal greeting, often used with friends.
* ¿Qué pasa? (What's happening?) - A very casual greeting, used with close friends.
Specific to Cuba:
* ¿Qué a'ta? - A common Cuban greeting, similar to "What's up?"
* ¡Ay, mi vida! - A warm and affectionate greeting, often used with family and close friends.
The best way to say hi in Cuban Spanish depends on your relationship with the person and the situation. If you are unsure, it is always best to err on the side of formality by using "Buenos días", "Buenas tardes", or "Buenas noches".