This is the 712th most frequent Norwegian word.
hvem
"Who"
Hvem is used here to inquire about the identity of the person knocking.
Hvem er det som banker på døren?
Who is it that is knocking on the door?
Hvem is used here to ask about the choice of people to be invited.
Hvem skal vi invitere til bursdagen vår?
Who should we invite to our birthday?
Hvem is used within a subordinate clause to reference the person met.