At the airport B1
From the check-in desk to the gate.
I'd like to check in — request check-inI'd like to check in, please. (polite)
Checking in — here's my passport. (casual)
catch a flight — travel by planeA: Are you coming to the meeting later?
B: I can't, I need to catch a flight this afternoon.
window or aisle — choosing a seatCould I have a window seat, please? (polite)
Window or aisle? — Window, thanks. (casual)
At the check-in desk
Agent: Good morning! Where are you flying today?
You: Hi, I'd like to check in for the flight to Rome.
Agent: Of course. Window or aisle?
You: A window seat, please.
Talking about the flight
Jo: Is it a direct flight?
Sam: Yeah, no stops. But we take off at six — so early!
Jo: Better not miss it. When should we get there?
Sam: Two hours before, to be safe.