This is the 187th most frequent Finnish word.
johon
"Johon" means "to which" or "into which" in English.
Relative pronoun usage, indicating the target house in the clause.
Talo, johon haluan muuttaa, on Helsingissä.
The house to which I want to move is in Helsinki.
Relative pronoun usage, linking the key with the door in question.
Tässä on ovi, johon kadotin avaimen.
Here is the door to which I lost the key.
Relative pronoun usage, specifying the road being referred to.