Mitä "pakkasta" ja "pilvista" tarvoittavat?
Are these words adverbs?
And how can I make adverbs from nouns and adjectives? Or should I just learn them by heart?
I've searched a little and made a conclusion:
I had sentences: On pilvista.(It's cloudy) On sumuista.(It's foggy) On pakkasta. On selkeää.
Then I found that these words have their initial forms (Nominatiivi): pilvinen, sumuinen, pakkanen, selkeä.
And they're used in these sentences in Partitiivi-case.
So why do we use them like that? Is it a special function of Partitiivi?