Formal:
* Buenos días: Good morning (used until noon)
* Buenas tardes: Good afternoon (used from noon to evening)
* Buenas noches: Good evening (used from evening until late night)
* ¿Cómo está? How are you? (formal singular)
* ¿Cómo están? How are you? (formal plural)
Informal:
* Hola: Hello (used anytime)
* Buenos días, ¿qué tal? Good morning, how are you? (used until noon)
* Buenas tardes, ¿qué tal? Good afternoon, how are you? (used from noon to evening)
* Buenas noches, ¿qué tal? Good evening, how are you? (used from evening until late night)
* ¿Cómo estás? How are you? (informal singular)
* ¿Cómo están? How are you? (informal plural)
* ¿Qué más? What's up?
* ¿Qué hay? What's up?
* ¿Cómo va? How's it going?
Common phrases:
* ¿Cómo te va? How are you doing?
* Mucho gusto (meaning "nice to meet you") is often used when meeting someone for the first time.
* Qué gusto verte (meaning "nice to see you") is a common greeting when meeting someone you know.
Regional variations:
* In some regions, people might use "Día" instead of "Buenos días", "Tarde" instead of "Buenas tardes", and "Noche" instead of "Buenas noches".
* You might hear "¿Qué hubo?" (meaning "What's up?") in certain areas.
Important Note: Colombians are generally very friendly and welcoming. It's always a good idea to greet people with a smile and be polite.