Formal:
* Bem-vindo(a) a Lisboa: This is the most formal and literal translation, meaning "Welcome to Lisbon". You would use this for a formal occasion or when addressing someone you don't know well.
Informal:
* Seja bem-vindo(a) a Lisboa: This is a slightly more polite way of saying "Welcome to Lisbon", still appropriate for most situations.
* Bem-vindo(a) a Lisboa! This is the most common and informal way of saying "Welcome to Lisbon!". You would use this with friends, family, or people you know well.
Note:
* "Bem-vindo" is used for male singular, "Bem-vinda" is used for female singular, and "Bem-vindos/Bem-vindas" is used for plural.
You can also add a phrase like "é um prazer recebê-lo(a)" which means "It's a pleasure to welcome you".
Here are some examples:
* "Bem-vindo a Lisboa, é um prazer recebê-lo." (Welcome to Lisbon, it's a pleasure to welcome you.)
* "Seja bem-vinda a Lisboa, divirta-se!" (Welcome to Lisbon, have fun!)
* "Bem-vindos a Lisboa, espero que gostem da cidade!" (Welcome to Lisbon, I hope you enjoy the city!)