Thread: Cases of Sky and Cloud

Could someone tell me what the Genitive Plurals of "Cloud" and "Sky/Heaven" would be? According to the grammarbook i've got you just take off the last letter, but "Oblak" and "Neb" look incorrect to me. Maybe they're irregular or something? I know those generic rules for endings don't work alot of times. Especially in the Genitive Case. Any help is much appreciated.

For clouds it's "облаков", I don't know why.

For sky the word "небесa" is usually used in plural ("небеса" also is a word in its own right, it means sky in the poetic or religious sense - the same as "heaven").
So it's like this:

Case - Sing., Plural
Nom. - небо, небеса
Gen. - неба, небес
Dat. - небу, небесам
Acc. - небо, небеса
Instr. - небом, небесами
Prep. - небе, небесах

So for clouds it declines the same as a masculine noun with a consonant ending. ^_^, I should've guessed that since other nueter nouns take masculine endings also. As for Nebesa..I had no clue there was a separate word for sky in the plural. So thanks a million for that, gRomoZeka!!