Breakdown of Hylly, jolla kirjat ovat päällekkäin, on kallis.
olla
to be
kirja
book
kallis
expensive
hylly
the shelf
Questions & Answers about Hylly, jolla kirjat ovat päällekkäin, on kallis.
How is päällekkäin formed here?
It uses the mutual arrangement suffix -kkäin attached to the root of pää (head/top). Because pää contains front vowels (ä), vowel harmony dictates we use -kkäin instead of -kkain. Together, it describes the books as being stacked 'on top of each other'.
Why do we use jolla instead of jossa for 'on which'?
The relative pronoun joka takes the adessive case (jolla) because it refers back to hylly (shelf). In Finnish, you put things on a shelf (hyllyllä), not in it, so we must use the 'on' case here.
Why are there two verbs (ovat and on) so close to each other, separated only by a comma?
The comma marks the end of the relative clause. Ovat is the verb for the inserted relative clause (jolla kirjat ovat päällekkäin), while on is the verb for the main sentence (Hylly... on kallis).
Could I say toistensa päällä instead of päällekkäin?
Yes, toistensa päällä translates directly to 'on top of each other' and is grammatically correct. However, for objects that are physically stacked in a pile, the adverb päällekkäin is much more concise and natural in everyday Finnish.