. I'm a lost tourist in London, and I don't know where to go. I'm going to talk to the ticket man in the London Underground and see if he can help me. "Hello, Mr. ticket man. I would like a ticket to Piccadilly." The man starts talking to me. "Blah, blah, blah." He asks me a question. I don't know what to say, so I need to make a noise. "Ah." These are noises that give you time to think about your answer. "Ah. I would like a ticket, please, to Piccadilly Circus." Or I could say, "Urgh, I want a ticket please." Or "Urm, I want to go to --." Or the other one would be, "Mmm, I want a ticket." Okay. Good.