This is the 260th most frequent Finnish word.
kuka
"Who"
The word 'kuka' is used as an interrogative pronoun to ask about the identity of a person.
Kuka sinä olet?
Who are you?
Here, 'kuka' is used as a relative pronoun to refer to the person who committed an action, introducing a subordinate clause.
Hän tietää, kuka varasti pyörän.
They know who stole the bicycle.
In this instance, 'kuka' is combined with the colloquial particle '-han' for politeness or speculation, maintaining its role as an interrogative pronoun.