Excuse me!
SCU-zi — two syllables, stress on the first. The 'sc' before 'u' is hard, like 'sk'.
To attract the attention of a waiter. This is the most important single word in a restaurant context — learn it before anything else.
'Scusi' is the formal imperative of 'scusare' (to excuse). It is used to attract attention politely in formal contexts (strangers, service staff). The informal equivalent is 'scusa'. Never say 'waiter!' or 'oi!' — 'scusi' is always correct.
Permesso!
Excuse me! / May I?
Used when physically passing by someone rather than calling attention from a distance
Mi scusi.
Excuse me.
Slightly fuller form — 'mi' (me) added for extra politeness
Senta!
Listen! / Excuse me!
'Senta' is the formal imperative of 'sentire' — used familiarly in Italian restaurants to call a waiter
In Italian restaurants it is completely normal to call the waiter by saying 'Scusi!' loudly enough to be heard. There is no buzzer or call system — eye contact and a clear 'scusi' is the Italian way. Staff are not offended and will come immediately.