Confirm with me tomorrow whether you can come.
'Confermami' = con-FER-ma-mi. 'Riesci' = rie-SCI, stress on first syllable.
Use this when you need a definite confirmation from someone before finalising plans. It gives them time to check their diary while setting a gentle deadline. The 'mi' at the end emphasises that they are confirming directly to you.
'Confermami' = 'confirm to me' — the imperative 'conferma' + indirect object 'mi' attached to the end. 'Se riesci a venire' = 'whether you manage to come' — 'riuscire a' + infinitive = 'to manage to do something'. The 'se' here introduces an indirect question.
Fammi sapere entro giovedì.
Let me know by Thursday.
'Fare sapere' (to let know) — very common Italian expression
Hai confermato tutti?
Have you confirmed with everyone?
Group organiser checking their list
Siamo in attesa di risposta.
We are waiting for a reply.
Slightly more formal — suitable for group invitations
Italian RSVPs ('conferme') are notoriously unreliable at the informal level — Italians often say 'vengo sicuramente' (I am definitely coming) and then cancel at the last minute, or say they will 'try to come' and then turn up. Event organisers learn to plan for a 20-30% variation from confirmed numbers. It is part of Italian social elasticity.