"It's your birthday, order anything you want." "Well... did you really mean anything?" "Yes, go ahead. Order the lobster, I can see you're looking at it." "I'm going to read this aloud, and I'd like to make notes of any places where I make mistakes in pronunciation." "OK." "Are you ready?" "Yes, go ahead." "I leave this rule for others when I'm dead, Be always sure you're right—then go ahead!"--David Crockett "Your reservation is complete. I have a reservation number for you." "Hang on, I need to find a pencil. OK, go ahead." "31415926535."

The idiom "Go ahead" has such a variety of uses in the English language. Please do something: "Go ahead" and build it. To go ahead of someone: May I "go ahead" of you in line. To go ahead with something: Let's "go ahead" with arranging a party. To go ahead quickly: "Go ahead" get the job done. As a verb: . To move forward in front of someone or something: We walked in the right lane to let the bicycles "go ahead" of us. To continue even if there is a concern: The party will "go ahead" as scheduled even if it rains. To begin, in cases where waiting or planning is involved. I have to study for an exam — "go ahead" and play without me. To do something before someone else: Whenever we stand in line, my brother always "goes ahead" of me.

Go ahead, is informal and can mean that you are giving your permission to someone else. "You can go ahead and get started if you want to." Or it can literally mean to let someone walk in front of you. Imagine you are walking up to a door and someone else arrives at the same time. You both reach for the handle. You laugh and say, "Go ahead." This is very common in the US. It shows respect by letting someone else go before you.