Hello:
* Olá! (Formal and informal) - This is the most common and versatile greeting.
* Oi! (Informal) - A more casual greeting, often used with friends and family.
* Bom dia! (Good morning) - Used until midday.
* Boa tarde! (Good afternoon) - Used from midday until evening.
* Boa noite! (Good evening/Good night) - Used from evening onwards.
Goodbye:
* Tchau! (Informal) - The most common way to say goodbye.
* Até logo! (See you soon!) - A more formal way to say goodbye.
* Até mais! (See you later!) - Similar to "até logo."
* Adeus! (Farewell!) - Used for a more permanent goodbye.
Remember:
* You can use "Olá" and "Tchau" in almost any situation.
* When in doubt, it's always safe to use the more formal greetings.
* Brazilians are generally friendly and welcoming, so don't worry about getting it exactly right.