Breakdown of Куда мы идём? На стадион!
мы
we
на
on, at / by (transport) / to (a place) / to (in answer to)
куда
where to
идти
to go (on foot) / to proceed, go (of a process)
Questions & Answers about Куда мы идём? На стадион!
Why use куда instead of где for the word where?
Где means where at (a fixed location), but here we are asking about the destination of our movement (where to). For destinations, you must always use куда.
Does идём mean we are walking or driving?
Идём specifically means going on foot. If you were driving or taking a bus to the stadium, you would use a different verb, like едем.
Why do we use на instead of в for going to the stadium?
While в is usually used for going inside enclosed buildings, на is used for open or flat spaces, as well as events. Because a stadium is traditionally an open-air venue, it pairs with на.
Shouldn't the word стадион change its ending because it is the destination?
It is in the Accusative case here, which is the case used for destinations! However, стадион is a masculine inanimate noun (it ends in a consonant and is not a living being). For these types of nouns, the Accusative case form is exactly the same as the dictionary form.