Explain the reason for your request.
A person should only remember the moment when he was very much in a hurry somewhere, and he had to wait in line for something important. Most likely, he did not achieve something good, if he simply asked: "Can I pass first?". But the likelihood of persuading someone to agree to this proposal would have increased by more than 50 percent if he had added something very important: the reason. "Can I pass first because I really need to catch my flight?" Or even: "Can I pass first, I'm in a very big hurry?" The more requests, the more reasons a person must provide an opponent to really increase your chances of getting what he wants.