В аэропорту я должен сдать багаж.

At the airport, I have to check in my luggage.

Breakdown of В аэропорту я должен сдать багаж.

• я: I
• в: at
• аэропорт: the airport
• должен: must

Questions & Answers about В аэропорту я должен сдать багаж.

Why is it в аэропорту, not в аэропорте?

Because аэропорт has a special location form after в when it means in/at the airport: в аэропорту.

This is an old pattern that survives with some masculine nouns, especially places:

• в лесу = in the forest
• на мосту = on the bridge
• в порту = in the port
• в аэропорту = at the airport

So this is not the ordinary prepositional ending -е, but a special locative-type ending -у.

What case is аэропорту in?

It is traditionally called the prepositional case, though more specifically many grammars treat forms like в аэропорту as a special locative use.

Here, в means in/at, so it takes a location form:

• в аэропорту = at the airport

Compare:

• в аэропорт = to the airport
• в аэропорту = at the airport

So the case/form helps show the difference between movement toward a place and location in a place.

Why is багаж unchanged? Shouldn’t the object have a different ending?