can I get

Dumb way of asking for something in a bar or diner, which gives the impression that you've never actually understood how to ask for anything. If you say: "Can I get a cappuccino?" to a barrista, they're entitled to respond: "You can if you want, but they actually pay me to get things for you and I suspect your job is better paid than mine, so why don't I do the getting and you do the asking..." You can always tell people who understand how to be a customer. They say: "Can I have a cappuccino?"