Formal:
* Benvenuti/Benvenuta/Benvenute: (plural, for multiple people)
* Benvenuto/Benvenuta: (singular, for one person)
* Bentornato/Bentornata/Bentornati/Bentornate: (Welcome back)
Informal:
* Ben arrivato/Ben arrivata/Ben arrivati/Ben arrivate: (Welcome, more casual)
* Ciao! (Hello, informal greeting that can also imply welcome)
Other:
* Siete i benvenuti! (You are welcome!) - A more emphatic way to welcome someone.
Example:
* "Benvenuti al nostro ristorante!" (Welcome to our restaurant!)
* "Benvenuto a casa!" (Welcome home!)
* "Ciao, come stai?" (Hello, how are you?) - This can also be used to welcome someone in a casual setting.
The best way to choose the right phrase depends on the situation and your relationship with the person you are welcoming.