Breakdown of Pilvet, jotka muodostuvat nyt, ovat mustia.
olla
to be
nyt
now
musta
black
joka
who / which (relative pronoun)
Questions & Answers about Pilvet, jotka muodostuvat nyt, ovat mustia.
Why do we use muodostuvat here instead of muodostavat?
Muodostua has the -tua suffix, making it an automative verb. This means the action happens by itself without an outside agent. The clouds are forming naturally, so we use muodostua (to form by itself). The base verb muodostaa means to form or create something, which would require an object.
Why is the relative pronoun jotka used instead of mitkä?
Jotka is the plural form of joka, which is used to refer back to a specific noun—in this case, pilvet (the clouds). You would only use mikä or its plural mitkä if referring back to a whole clause, a superlative, an indefinite pronoun, or in a direct question.
Why is the adjective mustia in the partitive plural rather than the nominative plural (mustat)?
When describing a plural subject (pilvet) with an adjective and the verb olla (to be), the adjective usually takes the partitive plural. If you used the nominative plural mustat, it would change the meaning to "The clouds that are forming now are the black ones."
Does the verb in the relative clause have to match the plural pronoun jotka?
Yes! Because jotka refers back to the plural pilvet, it acts as a plural subject for its own clause. That is why the verb takes the plural ending -vat to become muodostuvat.