dai
/dye/ · interjection
come on! / oh come on / let's go
look it up on WordReference ↗In context
Dai, andiamo, è tardi!
Come on, let's go, it's late!
Technically dai is the verb dare (to give), but as an interjection it's pure encouragement, impatience, or disbelief — all depending on delivery.
Cheering someone on: "Dai dai dai!" — go go go! Coaxing a friend: "Dai, vieni!" — come on, come! In mock outrage: "Ma dai!" — oh, come ON.
Short, punchy, endlessly useful. Italians use it dozens of times a day.