"The cloud is very beautiful" should also be correct.
Trying to line up Korean and Japanese sentence enders is amusing, hah. 네 is like よ (and not ね), 요 adds politeness (yet hearing ㄹ까요 sounds like a mild attack if your head is in Japanese mode). What fun. :P
雲 は きれい だ よ。
-네 is used to express surprise or wonder.
크네: (it’s) huge!
So it's an extra "exclamation mark" that affects syllable count rather than statement intonation.
Very useful, thank you!
So there is the exclamation mark at the end of the sentence.
'clouds are really beautiful' was not accepted
'-네' is a declarative sentence