Breakdown of Tämä on se hiljainen kulma, josta näet koko pääkadun.
tämä
this
olla
to be
se
it / he / she (of a person) / that
koko
whole
Questions & Answers about Tämä on se hiljainen kulma, josta näet koko pääkadun.
Why is the relative pronoun in the form josta here?
Josta is the elative case (meaning "from" or "out of") of the relative pronoun joka. Because you are looking from the corner, Finnish expresses this as "out of which", hence josta. It links back to the word kulma (corner).
Finnish doesn't usually have words for "a" or "the". Why is se used before hiljainen kulma?
While it literally means "that" or "it", se is often used in Finnish to point out a specific thing, acting very much like the English definite article "the". It emphasizes that this is the specific quiet corner being talked about.
Why is pääkatu (main street) in the form pääkadun?
It is the direct object of the verb näet (you see). Because the action is complete (you see the entire street) and the sentence is affirmative, the object takes the genitive-like ending -n.
Since pääkadun gets an -n ending, why doesn't koko (whole) change to match it?
The word koko is a special modifier in Finnish because it is completely indeclinable. This means it never takes any case endings, no matter what form the noun it describes is in.